From e0c6872cf40896c7be36b11dcc744620f10adf1d Mon Sep 17 00:00:00 2001 From: Norbert Preining Date: Mon, 2 Sep 2019 13:46:59 +0900 Subject: Initial commit --- info/ltx3pub/l3d002e.tex | 1599 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1599 insertions(+) create mode 100644 info/ltx3pub/l3d002e.tex (limited to 'info/ltx3pub/l3d002e.tex') diff --git a/info/ltx3pub/l3d002e.tex b/info/ltx3pub/l3d002e.tex new file mode 100644 index 0000000000..52e5d5f036 --- /dev/null +++ b/info/ltx3pub/l3d002e.tex @@ -0,0 +1,1599 @@ +%%% ==================================================================== +%%% @LaTeX3-article{ LaTeX3-LTX3-002e, +%%% filename = "l3d002e.tex", +%%% archived = "ctan:/tex-archive/info/ltx3pub/", +%%% related-files = "part of l3d002.tex", +%%% author = "David Rhead", +%%% doc-group = "Project core team", +%%% title = "Some ideas for improving {\LaTeX}\\ General", +%%% version = "1.1", +%%% date = "18-Mar-1993", +%%% time = "20:19:36 GMT", +%%% status = "public, official", +%%% abstract = "Ideas and suggestions from David Rhead for +%%% improving various areas in LaTeX", +%%% note = "prepared for the workshop at Dedham 91", +%%% keywords = "", +%%% project-address = "LaTeX3 Project \\ +%%% c/o Dr. Chris Rowley \\ +%%% The Open University \\ +%%% Parsifal College \\ +%%% Finchley Road \\ +%%% London NW3 7BG, England, UK", +%%% project-tel = "+44 171 794 0575", +%%% project-FAX = "+44 171 433 6196", +%%% project-email = "LTX3-Mgr@SHSU.edu", +%%% copyright = "Copyright (C) 1993 LaTeX3 Project +%%% All rights reserved. +%%% +%%% Permission is granted to make and distribute +%%% verbatim copies of this publication or of +%%% coherent parts from this publication provided +%%% this copyright notice and this permission +%%% notice are preserved on all copies. +%%% +%%% Permission is granted to copy and distribute +%%% translations of this publication or of +%%% individual items from this publication into +%%% another language provided that the translation +%%% is approved by the original copyright holders. +%%% +%%% No other permissions to copy or distribute this +%%% publication in any form are granted and in +%%% particular no permission to copy parts of it +%%% in such a way as to materially change its +%%% meaning.", +%%% generalinfo = "To subscribe to the LaTeX3 discussion list: +%%% +%%% Send mail to listserv@vm.urz.uni-heidelberg.de +%%% with the following line as the body of the +%%% message (substituting your own name): +%%% +%%% subscribe LaTeX-L First-name Surname +%%% +%%% To find out about volunteer work: +%%% +%%% look at the document vol-task.tex which can +%%% be obtained electronically, see below. +%%% +%%% To retrieve project publications electronically: +%%% +%%% Project publications are available for +%%% retrieval by anonymous ftp from ctan hosts: +%%% ftp.tex.ac.uk +%%% ftp.dante.de +%%% ftp.shsu.edu +%%% in the directory /tex-archive/info/ltx3pub. +%%% +%%% The file ltx3pub.bib in that directory gives +%%% full bibliographical information including +%%% abstracts in BibTeX format. A brief history +%%% of the project and a description of its aims +%%% is contained in l3d001.tex. +%%% +%%% If you only have access to email, and not ftp +%%% You may use the ftpmail service. +%%% Send a message just containg the word +%%% help +%%% to ftpmail@ftp.shsu.edu +%%% for more information about this service. +%%% +%%% For offers of financial contributions or +%%% contributions of computing equipment or +%%% software, contact the project at the above +%%% address, or the TeX Users Group. +%%% +%%% For offers of technical assistance, contact the +%%% project at the above address. +%%% +%%% For technical enquiries and suggestions, send +%%% e-mail to the latex-l list or contact the +%%% project at the above address.", +%%% checksum = "28553 1599 11400 79963", +%%% docstring = "The checksum field above contains a CRC-16 +%%% checksum as the first value, followed by the +%%% equivalent of the standard UNIX wc (word +%%% count) utility output of lines, words, and +%%% characters. This is produced by Robert +%%% Solovay's checksum utility.", +%%% } +%%% ==================================================================== + +\chapter{Citations and reference-lists} +\label{citing} + +\section{Some e-mail comments} + +\begin{footnotesize}\begin{verbatim} +From: Sebastian Rahtz +Date: Tue, 7 Aug 90 15:33:13 bst + +... writes: + > One of the most common mistakes that I see from LaTeX users is typing + > \maketitle before \begin{document}; since this causes horrible things to + > happen, perhaps we should make sure that this causes an error. +and why not put \bibliographystyle before \begin{document}, where it +belongs.. +\end{verbatim}\end{footnotesize} +\begin{center} --- \end{center} +\begin{footnotesize}\begin{verbatim} +From David Rhead ... +Date: 13 Aug 90 17:39:39 + +Sebastian suggested + "and why not put \bibliographystyle before \begin{document}, where it + belongs.." + +This might need thinking through, bearing in mind that certain types of +document may have more than one list of references. For example: +Manuals produced by software houses, e.g. the SPSS-X documentation. + Such manuals may, in effect, divide citations into 2 categories: + 1. references to other manuals produced by the software house, + which might be cited using a "short title" scheme + 2. references to other literature, which might be cited using + an author-date scheme. + E.g. the SPSS-X Introductory Statistics Guide generally uses + author-date, but gives the full reference to the SPSS-X User Guide + in its preface and thereafter refers to it as "SPSS-X Users Guide". + The software house may list its own publications in the preface to + its manual, putting the list of references to other literature + at the back of the manual. To support this sort of thing would + require something like + \documentstyle{manual} + \begin{document} + ... + % \xxx represents a command that embeds \bibliography-like + % information in a preface. "software-house" represents + % a style that software houses seem to like where the + % reference is embedded in an explanatory paragraph. + \xxx[Our other manuals]{software-house}{our-manuals} + \chapter{...} + ... + \bibliography[Other people's stuff]{author-date}{other-literature} + where \xxx and \bibliography are assumed to have + * an optional argument to specify a title + * an argument to specify the scheme (like \bibliographystyle does) + * an argument to specify the bib files. +Books. It might be sensible to divide a book's references into 2 lists, e.g. + "References" and "Further reading". E.g. the draft revised British + Standard for theses suggests having "Bibliography" as well as "List + of references". It might also be sensible to have different styles + for the 2 lists: perhaps a concise style for the "References", + but a style that prints some extra information about the + "Further reading". The author might want to specify something like + \documentstyle{...} + \begin{document} + ... + \bibliography[References]{author-date}{specific-books} + \bibliography[Further reading]{annotated}{general-books} + ... + [Such sub-division seems to be countenanced by the gurus, e.g. Chicago + Manual of Style (p. 425) and Butcher's Copy-editing (p. 183,192).] +Unfortunately, such considerations lead to more questions like "How does +one arrange that \cite gives (...) around author-date citations, but not around +short-title citations?" and "Can a root file have several bbl files and what +would they be called?", and I don't know the answers. + +At the moment, I just think that it would be better to refrain from putting +\bibliographystyle before \begin{document} until the implications for +documents that have more than one list of references have been thought through. +Otherwise there might be a change to "\bibliographystyle before +\begin{document}" at LaTeX 3.0 followed by another change (e.g. to +"bibliography style as argument of \bibliography") in some subsequent LaTeX. +\end{verbatim}\end{footnotesize} +\begin{center} --- \end{center} +\begin{footnotesize}\begin{verbatim} +From: Sebastian Rahtz +Date: Tue, 14 Aug 90 10:00:33 bst + + > "and why not put \bibliographystyle before \begin{document}, where it + > belongs.." +David Rhead has some sensible cautionary remarks, and I would concur +with his underlying thesis that the bibliography support in +LaTeX/BibTeX has definite lacunae. He identifies the problem + + > This might need thinking through, bearing in mind that certain types of + > document may have more than one list of references. For example: + +and suggests a formulation along the lines of + > \bibliography[References]{author-date}{specific-books} + > \bibliography[Further reading]{annotated}{general-books} + +this is interesting, but nobody will thank anyone for changing the +basic syntax of a LaTeX command in the near future. I would suggest +retaining \bibliography as it is documented, and implementing David's +suggestions with others as new commands. ... such as separate +bibliographies for chapters - whatever LL or OP say about it being so much +work to do a multi-chapter book that sets of bibliographies being not +much more work, I don't see why we shouldn't get it in one day. People +*do* want it. I am on my fourth conference proceedings in as many +years, and I dont enjoy building the slightly complicated Makefile to +get all the references in the right place up to date. + +but I continue to say that the user who puts \bibliographystyle before +\begin{document} is behaving intuitively, and should therefore be +allowed to do it. lets keep `bibliography' for the relatively simple +academic type that LL and OP envisaged, and invent a new term +(\reference?) for what David Rhead is talking about. +\end{verbatim}\end{footnotesize} +\begin{center} --- \end{center} +\begin{footnotesize}\begin{verbatim} +From: "Nelson H. F. Beebe" +Date: Sat, 18 Aug 90 17:15:10 CET + +I just hit what I view as a design flaw in thebibliography +environment. It was precipitated by the following BibTeX +bibliography entry in the .bbl file: + +\bibitem{Steele:floating-point-output} +Guy~L. {Steele Jr.} and Jon~L. White. +\newblock How to print floating-point numbers accurately. +\newblock {\em ACM SIG\-PLAN Notices}, 25(6):112--126, June 1990. +\newblock In electronic mail dated Wed, 27 Jun 90 11:55:36 EDT, Guy +Steele reported that an intrepid pre-SIGPLAN 90 conference +implementation of what is stated in the paper revealed 3 mistakes: + + \begin{enumerate} + \item + Table~9 (page 125):\par\noindent + \begin{tabular}{ll} + for & {\tt -1:USER!({"}{"});} \\ + substitute & {\tt -1:USER!({"}0{"});} + \end{tabular} \par\noindent + and delete the comment. + \item + Table~10 (page 125):\par\noindent + \begin{tabular}{ll} + for & {\tt fill(-k, {"}0{"})}\\ + substitute & {\tt fill(-k-1, {"}0{"})} + \end{tabular} + \item + Table~5 (page 124):\par\noindent + insert {\tt k <-- 0} after assertion, and also delete {\tt k + <-- 0} from Table~6. + \end{enumerate} + +The effect of this is that the next bibliography entry gets +number 4, one more than the last enumerate counter. The reason +lies in latex.tex: + +% The thebibliography environment is a list environment. To save the +% use of an extra counter, it should use enumiv as the item counter. + +For now, I will switch to an itemize instead of enumerate. + +The question for this list is, is the saving of an extra counter +at what is usually almost the end of a document anyway worth this +design gotcha? I suggest not. +\end{verbatim}\end{footnotesize} +\begin{center} --- \end{center} +\begin{footnotesize}\begin{verbatim} +From: MITTELBACH FRANK +Date: Fri, 5 Oct 90 17:43:46 CET + +I would like to foward a mail from Nico which was a reaction +to some discussions at the Cork meeting. + +------------------------ forwarded mail ------------- +> +> here are some first thoughts on BibTeX and front matter. +> +> BibTeX +> ------ +> BibTeX is unfortunately not a database management system -- +> unfortunate in the sense that users have to think of a way to +> *really* manage the database, i.e. add, change, remove, sort, select, +> import and export entries. On my Atari I use a simple database +> program -- a real GEM program with mouse and buttons -- to maintain a +> literature database. I've written a conversion program that generates +> a .bib file from this database. This system works and is also used ny +> my ex-colleagues at the university. +> +> In general, working with BibTeX is cumbersome -- every time you add a +> reference to your document you have to run LaTeX, BibTeX, and LaTeX +> twice again -- and a lot of LaTeX users think it only pays off when +> your document/bibliography is above a certain length. +> +> What I would like to see in LaTeX is coding of the logical structure +> of every \bibitem. In version 2.09, BibTeX takes care of the logical +> structure and outputs formatted text. In other words: a part of the +> document, the one included by the \bibliography command, does not +> contain tags for the logical structure. Furthermore, if a user +> decides NOT to use BibTeX, he/she has to do the formatting completely +> by hand. +> +> Front matter +> ------------ +> Currently, an article starts with \title, \author and \date +> instructions. In the Elsevier styles I have added \address, +> \received, \revised and \accepted commands, and also a keyword +> environment, similar to the abstract environment. By doing so, we can +> automatically convert a LaTeX-coded document to an SGML-coded +> document. +> I think it is a bad idea to put the front matter information in a +> .bib record for the above reasons and also for the following reason: +> some parts of the front matter do not have to be re-used again in +> bibliographical entries, and therefore do not belong in the .bib +> database. +> Examples: list pf previous books in a series, LCC data, dedication, +> motto (books), keywords, date of receipt, revision, acceptance +> (articles). +> +... + +The last comment about the bad idea probably needs some +explanation: During the Cork conference we discussed the possibility +to use an extended version of bibtex, which is able to produce +several bibliogrphies at once, to format a title page (on request). + +The idea was that for larger documents one could set up a bibliography +entry for the document itself with all relevant information in it. +In the document itself the title would then be formated by a command, +say \titlefrombib{} which would make request bibtex to produce +a file containing all necessary information for producing the title. +This means that every journal that accepts LaTeX input would supply +a BibTeX style file which generates from a single bib entry such +a file. The advantages of this method would be that unused information +would produce no problem (the bst file would simply ignore them). +Another advantage would be that authors (for eample for TUGboat) would +already sending a bib entry along with his document. + +Of course, a standard way for simple document that generates titles +without using BibTeX should be availabe too. And the standard document +styles should also have their bst files for producing the title. + +This scheme if, of course only sensible (if at all) if \BibTeX is +able to produce several bbl files in one pass. + +I still think that such a feature has some promising possibilites +and would like to hear other opinions about it. +\end{verbatim}\end{footnotesize} +\begin{center} --- \end{center} +\begin{footnotesize}\begin{verbatim} +From: David Rhead +Date: 9 Oct 90 10:39:45 + +Frank forwarded some mail from Nico about BibTeX etc. + + +BIBLIOGRAPHIC DATABASE? + +I agree with Nico's comment about BibTeX not being a database management +system. I have the impression that some research workers really want a +system that will not only contain author, date, etc. for a paper/book, +but also a copy of the abstract and perhaps some reminders to themselves. +Thus, they want something that will both +(1) help (by supplying bibliographic details) when they are in the process + of writing a paper +and +(2) help them to search through all the papers they've ever read + until they come to something that is about a particular subject. + E.g. "give me all the papers about X", "what was that paper about Y?". + +It's unfortunate that Lamport/Patashnik used the term "bibliographic +database" (although I can't think of anything better offhand). It leads +to people thinking that BibTeX will do the things that they associate +with "database systems" these days. + +However, I think that to turn BibTeX into something that did more +than (1) would be too ambitious. We're going to have enough problems +finding someone to make BibTeX do (1) better. + +I think it would be better to treat (2) as a separate project, and to ask +"is (2) best done by adding database management features to BibTeX, +or would it be better done by adding BibTeX-like features to a +database management system?" I don't know what the answer is. + +For the time being, I think users will have to be left in an unsatisfactory +situation. If the "raw data" is kept in a "real database", the .bib file +is just yet another intermediate file. I seem to remember that +Sebastian Rahtz has set INGRES up so that INGRES can hold bibliographic +information and write it out in the form of a .bib file. It sounds as +though Nico is doing something similar with a different database +system. + +It seems sensible to use a "real database system" for what "real database +systems" are good at. Although it is clearly unsatisfactory to have a .bib +file that merely "shadows" a "real database" I can't think of anything better +that could be done quickly. [Perhaps a database expert might have some bright +ideas. Could such an expert write software that took an .aux file, generated +instructions in a "query language" to select the \cite-ed references, and +then produced a .bbl file (or equivalent) without there ever being a .bib file? +I don't know: I'm not a database expert. Even if they could, it +would probably still be useful to have a standalone program like BibTeX +that did task (1) in a database-system-independent way.] + +A salesman has sent me a leaflet about a piece of software called +EndNote which apparently seems to aim to do both (1) and (2) for Mac and PC +word-processor users. (It's not public domain, but then neither is INGRES.) +I see that it can export information for troff's "refer". He's coming to +see me at the beginning of November, so I'll ask if EndNote might be tailored +to read .aux files and produce .bbl files. I expect the answer will be +"no" or "only after a lot of work", but it does no harm to ask! +Perhaps one could have a public-domain BibTeX for task (1) with tailored +proprietary software for people who want (1)+(2). + +Conclusion: I can't think of an easy way of improving the "3 times +through LaTeX and once through BibTeX" business at the moment. I doubt +whether its worth making BibTeX into a proper database system, although +it might be worth making "a proper database system" do what BibTeX does. + + +CODING THE LOGICAL STRUCTURE OF EACH \BIBITEM? + +I can see the attraction of this. The list of references could be +held in the root file or \input or \include-ed from a .tex file +like everything else. There wouldn't need to be any special treatment +of .bbl files. + +However, in terms of project-management, it seems very convenient to regard +determination of the logical structure for bibliographic references +as a separate task which can be delegated to whoever volunteers +(if we can find them) to do another iteration on BibTeX. +It would be up to this person to specify the logical elements +for a reference, e.g. to agonise about whether ADDRESS is +the fundamental concept of whether it should be PLACEOFPUBLICATION. + +All that needs agreeing between the LaTeX 3.0 people and the +BibTeX worker (if we find one) is the form of interface, i.e. +what BibTeX passes back to (a) go where the \cite was and (b) go +in the list of references. There might need to be separate +interfaces for "reference by number", author-date and "short title" +[I'll have a go at suggesting what these might be in a future message] +but beyond that, the LaTeX 3.0 people need not be concerned +about the distinction between e.g. different author-date styles. +Thus, the BibTeX worker's considerations of matters such as +ADDRESS versus PLACEOFPUBLICATION can proceed in parallel with +the LaTeX 3.0 people's work on other matters. It wouldn't matter +much whether both projects were complete at the same time. + +If the LaTeX 3.0 people attempted to code the logical structure of +each \bibitem, this would mean that LaTeX 3.0 could not be finished +until the LaTeX 3.0 people had satisfied themselves about "What are +the fundamental types of publication (\bibitem{knuth-84}{book} or +\bibitem{knuth-84}{monograph}?), and what are the fundamental +items of bibliographic information about them? Did Lamport/Patashnik +get it right? E.g. ADDRESS versus PLACEOFPUBLICATION." The LaTeX 3.0 +people would presumably have to provide TeX code that sorted bibliographic +details out into the order required for a particular style e.g. "reference +by number in ACM style" (and perhaps provide a few style-options to +show how the details could be changed for a different convention, +e.g. author-date in APA style). I think that the LaTeX 3.0 work +is ambitious enough without taking this analysis on too. Attempting +to get the subdivision of \bibitem right could hold the rest of the +project up. + +Continuing to delegate the work on the logical structure of each \bibitem +to BibTeX might not be as elegant from the user's point-of-view as +getting LaTeX to do all the work (using structure information from +subdivisions of \bibitem and bibliography-style information from +\documentstyle) but I think the result would be available sooner and that +the user might prefer to have something better than LaTeX 2.09 soon, rather +than to have perfection not so soon. + +The two approaches (1) "put all the BibTeX work into LaTeX" (to take +account of the logical structure of each \bibitem), and (2) "make +BibTeX into a proper database management system" seem to be pulling +in different directions. I don't think one can do both (otherwise +you'd end up with LaTeX as a bibliographic database management system), +although one could do neither. + +For LaTeX 3.0, I'd be inclined to leave the contents of each \bibitem +(or the successor to \bibitem) as a "black box", to be filled in by the +user or by BibTeX. If someone does the analysis for BibTeX 2.0 (say), +the question could be considered again if there is ever a LaTeX 4.0 (!) + +[This all assumes that the SGML-ers have not analysed the structure +of a list of references and hence that someone has to do the analysis. +If the SGML-ers have done the anlysis (for a DTD, perhaps), could they +publish it?] + +Conclusion: I'd specify an interface between LaTeX 3.0 and BibTeX +that would support the "reference by number", author-date and (if +possible) "short title" schemes, but delegate the task of supplying +\bibitems (or whatever) to that specification to whoever updates BibTeX +and its .bst files. + + +FRONT MATTER INFORMATION IN A .BIB RECORD? + +The gurus of "how to do a list of references" seem to agree that +bibliographic details should be as they appear on the title page of +the article, book, etc. But there are many caveats: +* Several books by the same author in one bibliography should + follow the same style (Chicago Manual of Style, p. 441). +* There are potential problems with names like Tchaikovsky, + which may appear in different forms (Chaikovsky) on different + title pages, even though the works are all by the same person. + [British Standard BS 1629, p. 5] +* The part of the name not on the title page may be enclosed + in square brackets (Chicago, p. 441). +* If the name on the title page is a pseudonym, the author's + real name may be given in the bibliography in square brackets. + (Chicago, p. 442). +* Capitalization, punctuation, etc. of a title may be differ in a + bibliography from the conventions on the title page (Chicago, p. 447). + Similarly, compulsory line-breaks may be wanted on the title-page + but not in the list of references (\\, Lamport's book, p. 164). + For another example, consider "LaTeX: A Document Preparation System": + that's not how it appears on the title page. +* It may be necessary to use discretion about whether to regard + a subtitle as part of a title or to abbreviate a long title + (ISO standard 690, p. 5). +* A bibliography may give "place of publication" in a form that is + different to that on the title page, using discretion about: + - whether to list all places where the publisher has offices + or just one place + - whether to give further information (if the place of publication + is not widely known or could be ambiguous). + (Chicago, p. 456). +* A bibliography might give a publisher's name in a form that differs + slightly from that shown on the title page (Chicago, p. 458). + +I think that having a BibTeX that can produce several bibliographies at +once would be "a good thing". For example: +* for conference proceedings where each contribution may have its own + list of references +* for books that may have e.g. "References" and "Further reading" +* things like the SPSS manual (and other things produced by software + houses), which seem to give the software-house's related publications + in a preface, but put "academic references" at the end. + +However, I don't necessarily think that the same mechanism should +be used to "derive a publication's title-page from its .bib entry". +Traditionally, bibliography entries have been derived from title-pages +(with some human discretion), rather than the other way round, so its +probably safer to have software that imitates the tradition. One might +think of having things like +\begin{titlepage} + \author[bibliography-version]{titlepage-version} + \title[bibliography-version]{titlepage-version} + \place[bibliography-version]{titlepage-version} + \publisher[bibliography-version]{titlepage-version} +\end{titlepage} +\begin{copyrightpage} + \copyrightholder{...} + \isbn{...} +\end{copyrightpage} +in the .tex file (where the optional arguments allow humans to exercise +the discretion recommended by the gurus) and having LaTeX produce +perhaps a .bibitem file that the user can append to a suitable .bib file +(maybe after exercising a bit more discretion). LaTeX could put +information that might conceivably be used by a bibliographer in the +.bibitem file, but refrain from putting information that no bibliographer +would ever want to that file. TUGboat would get a .bib entry +with each article (but it would be derived automatically from the +article-heading, rather than used to automatically produce the +article-heading). + +[Conversely, if the Cork suggestion was adopted, and title-page +information was produced by some future BibTeX from a .bib file, there +would have to be some mechanism to allow for minor variations, e.g. + TITLE = "LaTeX: A Document Preparation System", + TITLEPAGETITLE = "LaTeX\\A Document Preparation System"] + +The problems that I mentioned in the context of "logical structure +of \bibitem" arise here too. To write .sty files for (say) book, report, +conference-proceedings and article, you only need to be clear about those +categories (as well as being a TeX wizard and having a lot of time, +perseverance and patience). To write .bst files with entry-types of book, +report, conference-proceedings, article, you need to be clear whether +they are distinct entry-types or not. [ISO 690 could be interpreted +as lumping books, reports and conference-proceedings all together +as "monographs".] You also need to be clear about the fields: +e.g. PLACE or ADDRESS. So the LaTeX 3.0 code for title-pages would +get held up (and hence LaTeX 3.0 as a whole would get held up) +while someone analysed "the structure of a \bibitem". +On the other hand, if LaTeX 3.0 wrote out a .bibitem file that wasn't +quite what some new BibTeX expected, it wouldn't matter very much, +and could be corrected once it was clear what was required. + +Conclusion: I'd like BibTeX to support multiple lists-of-references, +but think that "LaTeX producing .bib info from titlepage info" +might be better than "BibTeX producing titlepage info from .bib info". +\end{verbatim}\end{footnotesize} +\begin{center} --- \end{center} +\section{My e-mailed \lq\lq paper''} + +\subsection{Introduction} + +Since there are now plans for a new version of \LaTeX\ +\cite{lamport-86,m+s-89}, this may be a good time to consider +how a future version should deal with citations and reference-lists. + +My viewpoint is that of an advisor to authors who use \LaTeX\ 2.09. +As such, I'm often in the position of having to decide whether \LaTeX\ +acts inappropriately or whether an author is asking for something +inappropriate. Generally, I have the impression that \LaTeX\ 2.09 sometimes +makes it unnecessarily difficult for people to comply with the conventions that +are standard in \lq\lq academic publishing''. + +In making the suggestions that follow, I do realise that it's easier for me +to suggest that the volunteers developing \LaTeX\ 3.0 might provide some new +facilities than it is for a volunteer to find time to do the work! + +I assume that the reader is familiar with the relevant sections of +\cite{lamport-86}. + +\subsection{Conventions to be supported} +\label{conventions} + +\subsubsection{Citation schemes} +\label{basic-schemes} + +In mainstream publishing +\cite{bs-5605,bs-6371,butcher-81,chicago-82,gibaldi,huth,inter,iso-690,% +oconnor,page}, +there seem to be three basic schemes for citations and the corresponding +reference-lists: +\begin{description} +\item[reference by number] In this scheme, citations are normally numbered in + order of first citation. In particular, \lq\lq order of first citation'' + is used by over 300 biomedical journals \cite{huth,inter}, and is + specified in the ISO standard \cite{iso-690}. (Thus, in \BibTeX\ terms, + the usual numbering sequence is that given by {\tt unsrt}.) The number + is used as a \lq\lq label'' in the reference-list. +\item[author-date] There are two main forms of citation, depending on whether + or not the cited author's name occurs naturally in a sentence. In the + first case, the citation is of the form \lq\lq\ \dots\ (1972) + \dots\ '', whereas in the second case it is of the form \lq\lq\ \dots\ + (Crane, 1972) \dots\ ''. There are no \lq\lq labels'' in the + reference-list, which is arranged in alphabetical order of authors' + surnames (with supplementary rules for \lq\lq tie-breaking''). +\item[short form] The \lq\lq short form'' scheme is often used when citations + occur in footnotes. Typically, the first citation (or the first + citation in the current chapter) gives a fairly full reference but + subsequent citations use a short form. The \lq\lq short form'' may be + introduced within the first citation, or given in a table of + abbreviations. There are no \lq\lq labels'' in the reference-list, + which may be subdivided by \lq\lq type of cited document''. + The scheme is common in the humanities, but also seems to be used by + some software-houses when referring to their own publications (see, for + example, \cite{norusis}). +\end{description} +I think that, in order to make it straightforward to achieve, with \LaTeX, +the effects that people routinely achieve with traditional publishing +procedures, it is desirable that \LaTeX\ should provide explicit support for +all three citation schemes. + +Notice that: +\begin{itemize} +\item It is not, in general, possible to convert a document from one scheme + to another (e.g., from \lq\lq reference by number'' to author-date) + automatically. Some re-writing is required. +\item The number of items of information that need to be available + differ between the schemes. For a \lq\lq reference by number'' + citation, it is only necessary to keep track of one item + (the number), whereas for the other schemes it is necessary to keep + track of more than one item (i.e., the author and the date, or the + \lq\lq fairly full form'' and the \lq\lq short form'') + so that they can be used separately. +\item Occasionally, two different schemes may be used in parallel + within the same document. (For example, in \cite{norusis}, + a software-house seems to use \lq\lq short form'' when citing + its own publications, but author-date when citing other publications.) +\end{itemize} +Thus, it seems to me that the three schemes are best regarded as logically +distinct. + +However, within a particular scheme, there are variations of punctuation, etc., +that can be regarded as matters of \lq\lq house style''. +For example, some journals that have adopted a \lq\lq reference by number'' +scheme use bracketed numerals for citations, while others use superscripts. +Such variations can be accomodated by differences between style files. + +\subsubsection{Additional references} +\label{support-additional} + +In addition to a list of \lq\lq works cited'', some documents +have an additional reference-list that specifies \lq\lq further reading'' +or \lq\lq all sources consulted'' (see \cite[pp.\ 182 \& 192]{butcher-81}, +\cite[p.\ 40]{huth} and \cite[p.\ 22]{bs-4821}). There needs to be some +provision for typesetting such additional lists. + + +\subsection{Deficiencies in \LaTeX\ 2.09} +\label{2.09-problems} + +\subsubsection{Citations} +\label{2.09-citations} + +When used in conjunction with \BibTeX\ and \verb+\bibliographystyle{unsrt}+, +\LaTeX\ 2.09 makes a good job of organising citations (and sorting the +corresponding reference-list) according to the \lq\lq reference by number'' +scheme as required by many journals. + +Generally, however, \LaTeX\ 2.09 does not provide the breadth or depth +of facilities needed to support the variety of requirements for +mainstream publishing: +\begin{itemize} +\item It is unfortunate that the \lq\lq reference by number'' sequence obtained + most naturally by the do-it-yourself-er \cite[p.\ 73]{lamport-86} from + \LaTeX\ 2.09 (\lq\lq order of appearance within {\tt thebibliography}'') + is unlikely to be what the do-it-yourself-er's journal-editor requires + (which will usually be \lq\lq order of first citation''). The + do-it-yourself-er is given no warning (either in \cite{lamport-86} or by + the software) that sorting is likely to be needed. +\item Although one can use style-options such as {\tt apalike} and + {\tt aaai} to re-define \verb+\cite+ and {\tt thebibliography} + for an author-date scheme, there are many obstacles placed in the + user's way: + \begin{itemize} + \item The existence of the style-options is not documented in + \cite{lamport-86}. + \item If one finds a style-option in a (software) archive, it + may need modification to produce the precise effect required. + \item It is not obvious how one should refer separately to two + items (author and date) supplied via a \verb+\bibitem+ argument + originally designed for one. The do-it-yourself-er might + have to study style files such as {\tt aaai.sty} and {\tt bbl} + files such as those produced by {\tt aaai-named.bst} to + deduce how to do this. + \end{itemize} +\item The \lq\lq short form'' scheme seems unsupported. +\item At certain points in a document, an author my need to cite + several works at once. It may be necessary to specify a + page (or section, etc\@.) for each work. For instance, + \cite[p.\ 404]{chicago-82} suggests references of the form + \lq\lq (Kelley 1896a, 10; Kelley 1896b; Kelley 1907, 3)''. + This is not easy in \LaTeX\ 2.09, since \verb+\cite+'s + optional argument applies to the citation as a whole. The + author cannot supply a separate \lq\lq optional argument'' + for each work. (By contrast, {\sf EndNote}'s analogous facilities + \cite[p.\ 58]{endnote} seem to allow each individual work + to be given its own \lq\lq additional text''.) +\item It does not seem easy to use different schemes in parallel + within the same document. If \verb+\cite+ and + {\tt thebibliography} are defined as required for one scheme, + they will usually be unsuitable for any other. +\end{itemize} + +\subsubsection{Additional references} +\label{2.09-additional} + +As stated in section \ref{support-additional} an author may need to +typeset a list of \lq\lq further reading'' etc., in addition to +the usual list of \lq\lq works cited''. + +If using the {\tt thebibliography} environment from one of \LaTeX\ +2.09's standard styles for such additional references, an author will be +faced with the following problems: +\begin{itemize} +\item the title will be the same as that for the list of \lq\lq works + cited'', namely \lq\lq References'' for {\tt article} and + \lq\lq Bibliography'' for {\tt report} and {\tt book} +\item the \lq\lq labels'' (which may be appropriate in the list + of \lq\lq works cited'', particularly for the \lq\lq reference + by number'' scheme) will also appear in the + additional list (where they are inappropriate), because + both lists use the same definition of \verb+\bibitem+ +\item by default, the \lq\lq labels'' will not be unique, since + the \lq\lq works cited'' list and the \lq\lq additional references'' + list will both be numbered from one +\item it will be necessary to supply dummy {\it cite-key\/}s, + purely to satisfy the syntax required for a \verb+\bibitem+. +\end{itemize} + +\subsubsection{Other problems} +\label{2.09-other} + +The definitions of the {\tt thebibliography} environment in \LaTeX\ +2.09's standard styles: +\begin{itemize} +\item issue either a \verb+\section*+ or a \verb+\chapter*+ command, + using a {\it heading} of \lq\lq References'' for {\tt article} + and \lq\lq Bibliography'' for {\tt report} and {\tt book} +\item set {\it left-head\/} and {\it right-head\/} to either + \lq\lq REFERENCES'' or \lq\lq BIBLIOGRAPHY'' +\item do not arrange for a table-of-contents entry. +\end{itemize} +These definitions can cause problems when the {\it heading}, etc.\ +supplied by the standard style is inappropriate, or when a table-of-contents +entry is desired. +Admittedly, anyone who doesn't like the standard styles is free to +take copies of the style files and modify them to suit their requirements. +However, I have the impression that: +\begin{itemize} +\item among people who are competent to modify style files, + modification of these aspects of the standard styles is \lq\lq the + rule'' rather than \lq\lq the exception'' +\item those \LaTeX\ users who aren't particularly computer-literate + find the whole business mysterious, and seek out support staff + who have to modify these aspects of the style files for them. +\end{itemize} +Overall, this seems to be an area where \LaTeX\ 2.09 is failing to +\lq\lq free people from formatting concerns to allow them to +concentrate on writing'' \cite[p.\ 8]{lamport-86}. + +An associated problem is that modified style files may no longer be +compatible with standard utilities such as {\tt lablst}. + +\subsection{Introduction of new facilities} +\label{new-facils} + +It has been decided \cite{m+s-89} that \LaTeX\ 3.0 will be compatible with +\LaTeX\ 2.09 input files. Thus, in particular, \LaTeX\ 3.0 must define +\verb+\cite+ and \verb+thebibliography+ so that they have the same effect on +\LaTeX\ 2.09 input files as the \LaTeX\ 2.09 definitions do. This implies that +it would be difficult for \LaTeX\ 3.0 to (for example) define \verb+\cite+ +so that there can be an optional argument for each work in a multiple citation +and define \verb+\bibitem+ so that it can have an \lq\lq author'' argument and +a \lq\lq date'' argument. + +It therefore seems best to provide duplicates of the \LaTeX\ 2.09 facilities +in \LaTeX\ 3.0 (for \lq\lq backwards compatibility'') but to attempt to +provide new commands/environments in parallel so as to provide the required +functionality. The new facilities would be regarded as the \lq\lq normal'' +facilities, would be described in the body of the successor to \cite{lamport-86}, and +would be the natural choice for new users. The old facilities would be +regarded as \lq\lq deprecated'' and relegated to an appendix of the successor +to \cite{lamport-86}. + +Thus we can have both backwards compatibility and improved facilities +for the future. + +\subsection{Division of labour} +\label{div-of-labour} + +\subsubsection{Details needed for document \lq\lq as a whole''} + +The three basic citation schemes mentioned in section \ref{basic-schemes} +determine certain details of a document \lq\lq as a whole''. For each +citation, there must be an entry in a reference-list. Each entry in +the relevant reference-list must have associated information that can be +used in citations. + +\subsubsection{Details needed for reference-list, etc.} + +There are a lot of other details that need to be resolved. + +The information within each reference-list entry will probably need +formatting according to certain rules of \lq\lq house style''. +The information given in citations needs organising in a consistent way +(particularly for the \lq\lq short form'' scheme). + +Different people may want to assemble their reference-lists in different ways. +Some people may wish to \lq\lq do it themselves'' \cite[p.\ 73]{lamport-86} from +a physical card-index, while some may prefer to use \BibTeX\ to get details +from a {\tt bib} file. In some disciplines, proprietary systems such as +{\tt EndNote} \cite{endnote} seem popular (because they help the user to search +a database for literature to cite, as well as helping the user +incorporate details of the literature into a document). +Researchers may also wish to incorporate material obtained by searching +details held on a {\sc cd-rom}. + +A reference-list generally needs sorting into a particular order. Since the +list may occupy several pages, I assume that any sorting is best done outside +\LaTeX, either by other software (e.g., \BibTeX) or manually by the author. + +\subsubsection{\LaTeX\ and other software} + +It seems best to regard the movement of text-strings (e.g., an author's +surname) within the \lq\lq document as a whole'' as a task that is distinct +from the arrangement of details within the text-strings, and to assume a +\lq\lq division of labour'' in which the former task is performed by \LaTeX\ +while the latter is performed by some other software or manually by the author. +The \lq\lq division of labour'' between \LaTeX\ 2.09 and \BibTeX\ seems to set +a good precedent. + +This division of labour will lead to modular software. Once the +interface between a reference-list and the rest of the document has +been defined, people can use \LaTeX\ for the body of their document, +but can: +\begin{itemize} +\item experiment with different software (\BibTeX, {\sf EndNote}) + for formatting the details of their reference-lists +\item enhance the other software (e.g., \BibTeX) independently + of enhancements to \LaTeX. +\item lay their reference-lists out manually if they prefer. +\end{itemize} + +\subsection{\protect\LaTeX\ 3.0: A possible user interface?} +\label{what-to-do} + +\subsubsection{Specifications and names} + +If the reasoning given in sections \ref{conventions}, \ref{new-facils} +and \ref{div-of-labour} is accepted, consideration needs to be given to +the form that new commands/environments should take in order to support the +three basic citation schemes, and to provide facilities for \lq\lq additional +references''. In particular, it will be necessary to choose +names other than \verb+\cite+, {\tt thebibliography} and \verb+\bibitem+ (since +these names will be kept for the facilities provided for compatibility with +\LaTeX\ 2.09). + + +\subsubsection{Four sets of commands/environments} +\label{4-sets} + +It seems to me that it would probably be convenient to have three sets of +commands/environments for dealing with citations and the corresponding +reference-lists, each set specifically designed to implement a particular +citation scheme. Having three such sets gives scope for taking proper +account of the peculiarities of each scheme, without having one scheme +adversely affected by the peculiarities of another. + +To avoid the difficulties mentioned in section \ref{2.09-additional}, +it might also be worth having a specific environment for +\lq\lq additional references''. + +\LaTeX\ 3.0 might, for example, have commands/environments as specified +in the following table. + +\begin{center} +\begin{footnotesize} +\renewcommand{\arraystretch}{1.25} +\begin{tabular}{lccccccc} +\hline + & Citation & Environment for & Entry in \\ + & & reference-list & reference-list \\ +\hline +Reference by number & \verb+\numcite+ & {\tt numrefs} & \verb+\numentry+ \\ +\hline +Author-date & \verb+\dcite+ + & {\tt adrefs} & \verb+\adentry+ \\ + & \verb+\adcite+ & & \\ +\hline +Short form & \verb+\firstcite+ & {\tt sfrefs} & \verb+\sfentry+ \\ + & \verb+\sfcite+& & \\ +\hline +Additional references& --- & {\tt morerefs} & \verb+\moreentry+ \\ +\hline +{\it Analogue at 2.09} & \verb+\cite+ & {\tt thebibliography} + & \verb+\bibitem+ \\ +\hline +\end{tabular} +\end{footnotesize} +\end{center} + +Here it is assumed that: +\begin{itemize} +\item \verb+\numcite+ and \verb+\numentry+ have {\it key-list} and + {\it cite-key} (respectively) as their only mandatory arguments. +\item \verb+\dcite+ and \verb+\adcite+ have {\it key-list} as argument. + \verb+\dcite+ gives a citation of the form (1972), + while \verb+\adcite+ gives a citation of the form (Crane, 1972). + \verb+\adentry+ has three arguments: the {\it cite-key}, + the author (e.g., Crane), and the date (e.g., 1972). +\item \verb+\firstcite+ and \verb+\sfcite+ have {\it key-list} as argument. + \verb+\firstcite+ gives the form of citation to be used when a work + is first mentioned. \verb+\sfcite+ gives the short form + to be used in subsequent citations. + The arguments of + \verb+\sfentry+ might include: the {\it cite-key}, the form + of reference to be used at the first citation, and the short form + to be used subsequently. + Whereas \verb+\numentry+ and \verb+\adentry+ can \lq\lq introduce'' + the full reference (like \verb+\item+ starts a new item + \cite[p.\ 166]{lamport-86}), it may be better for \verb+\sfentry+ + to have the full reference as an argument, so that it can be used + as the default \lq\lq form to be used at first citation''. +\end{itemize} + +Although it would be desirable for the successors to the ``standard styles'' +to define facilities for all three citation schemes, other +\verb+\documentstyle+s need not define facilities for all three. For example, +a journal that wants its authors to use the author-date scheme would supply a +style file that only provides author-date facilities. + +\subsubsection{Further details} +\label{further-details} + +\paragraph{Reference by number} + +The \verb+\numcite+ and \verb+\numentry+ commands might take the form +\verb+\numcite{+{\it key-list}\verb+}+ and +\verb+\numentry{+{\it cite-key}\verb+}+. Notice that, since \verb+\numentry+ +is specifically designed for \lq\lq reference by number'', there is no need to +allow an optional {\it label} argument like that for \verb+\bibitem+. + +To conform to the ISO specification \cite{iso-690}, the successors to the +``standard styles'' would arrange for \verb+\numcite+ to give a citation of the form (24) +and for \verb+\numentry+ to give a reference-list entry of the form +\begin{description} +\item[{\rm 24.}] {\sc Crane, D.} {\it Invisible colleges.} \dots +\end{description} + +Perhaps \LaTeX\ 3.0 could use the {\tt aux} file to refine an initial estimate +of the width of the final \verb+\numentry+'s \lq\lq label'', so that the +do-it-yourself-er wouldn't need to supply a {\it widest-label\/} argument. + +\paragraph{Author-date} + +The commands \verb+\dcite+, \verb+\adcite+ and \verb+\adentry+ might +be defined to have the forms \verb+\dcite{+{\it key-list}\verb+}+, +\verb+\adcite{+{\it key-list}\verb+}+ and +\verb+\adentry{+{\it cite-key}\verb+}{+{\it author}\verb+}{+{\it date}\verb+}+. +The {\tt adrefs} environment would {\it not} have a {\it widest-label} +argument, since in this scheme entries in the reference-list are unlabelled. + +If such a definition of \verb+\adentry+ was documented in the successor to +\cite{lamport-86}, a do-it-yourself-er would be able to use the author-date +system just as easily as the \lq\lq reference by number'' system. + +To conform to the ISO specification \cite{iso-690}, the successors to the +``standard styles'' would arrange for \verb+\dcite+ to give a citation of +the form (1972), for \verb+\adcite+ to give a citation of the form +(Crane, 1972), and for \verb+\adentry+ to give a reference-list entry with no +label. + +\paragraph{Short form} + +The \verb+\firstcite+, \verb+\sfcite+ and \verb+\sfentry+ commands might +be defined as \verb+\firstcite{+{\it key-list}\verb+}+, +\verb+\sfcite{+{\it key-list}\verb+}+ and +\verb+\sfentry{+{\it cite-key}\verb+}[+{\it + fairly-full-form}\verb+]{+{\it short-form}\verb+}{+{\it + full-reference}\verb+}+. +Such definitions would, in effect, automate Butcher's manual method of +ensuring consistency \cite[p.\ 178]{butcher-81}. +Having {\it full-reference} as an argument means that the full reference +can be used as the default {\it fairly-full-form} (to be used when the work +is first cited \cite[p.\ 407]{chicago-82}). +The {\tt sfrefs} environment would {\em not} have a +{\it widest-label} argument. + +The successors to the ``standard styles'' would arrange for \verb+\firstcite+ +to produce the {\it fairly-full-form} and \verb+\sfcite+ to produce the +{\it short-form}.% +\footnote{% +This makes the pessimistic assumption that \LaTeX\ can not itself determine +whether a citation is the \lq\lq first citation'' of a particular work. +If someone was ingenious enough to produce code that determined whether a +citation is a \lq\lq first citation'', {\tt\ttbackslash firstcite} would be +unnecessary (except, perhaps, for the construction of tables of abbreviations +\cite[p.\ 414]{chicago-82}.)% +} +To conform to the ISO specification \cite{iso-690}, neither +\verb+\firstcite+ nor \verb+\sfcite+ +would add any punctuation (but, for example, a style file that implemented +the MLA conventions would have to add brackets \cite[ch.\ 5]{gibaldi}). +In the successors to the ``standard styles'', +the \verb+\sfentry+ would produce an entry with no label. + +People producing other style files would be free to implement other +conventions \cite[p.\ 168]{butcher-81}. + +Some works may have no bibliography or may have just a \lq\lq select +bibliography'' \cite[p.\ 168]{butcher-81}. For such works, it will still +be necessary to supply the details for use by \verb+\firstcite+ and +\verb+\sfcite+. It may therefore be worth allowing a form of +{\tt sfrefs} (e.g., \verb+\begin{sfrefs}[null]+) +that holds details of cited works but does no typesetting. + +\paragraph{Additional references} +\label{3.0-additional} + +Since the entries in an \lq\lq additional list'' will not be cited as such +(although an \lq\lq all sources consulted'' list may contain a duplicate of +a cited entry in a \lq\lq works cited'' list), the list will be typeset +without \lq\lq labels''. Even in a document that uses the \lq\lq reference by +number'' citation scheme (and so needs \lq\lq labels'' in the {\tt numrefs} +list), there will be no \lq\lq labels'' for the entries in an additional list. + +It therefore seems likely that the {\tt morerefs} environment could +be implemented as a variation of {\tt adrefs} or {\tt sfrefs}, the main changes +being: +\begin{itemize} +\item a change of title (but see section \ref{reflist-scope}) +\item absence of + {\it cite-key, author, date, fairly-full-form} and {\it short-form} + arguments. +\end{itemize} + +\subsubsection{Order within the reference-list} + +As stated in section \ref{div-of-labour}, it is probably best to leave +any sorting of the reference-list to some other software, or to the author. + +However, it might be possible for \LaTeX\ to provide a warning if a +reference-list is obviously in the wrong order. Perhaps: +\begin{itemize} +\item although there may be no easy alternative to numbering + \verb+\numcite+s in order of appearance within {\tt numrefs} + (even though \lq\lq order of first citation'' is usually what + is required), \LaTeX\ could give a warning if a \verb+\numcite+ + gave a number that exceeded the \lq\lq biggest number produced + by \verb+\numcite+ so far'' by more than one. +\item there could be a warning if an \verb+\adentry+ had an + {\it author} whose first letter came before the first letter of the + preceding \verb+\adentry+'s {\it author} in the alphabet. +\end{itemize} + +\subsubsection{Citation of a specific division} +\label{division} + +As stated in section \ref{2.09-citations}, provision needs to be made for +the citation of a particular division (e.g., page, section, chapter, +equation) of another work. The syntax of citation commands should +not only allow several works to be cited simultaneously, but should also +allow the relevant division of each work to be specified. + +From the author's point-of-view, there would be a variety of satisfactory +ways to specify citations that are to appear as +``[4, p.\ 10; 5; 6, p.\ 3]'', e.g. +\begin{verbatim} + \numcite{smith[p. 10],brown,jones[p. 3]} + \numcite{smith, p. 10; brown; jones, p. 3} + \numcite{smith & p. 10; brown; jones & p. 3} +\end{verbatim} +The precise syntax would have to take +account of the practicalities of programming a command that has to be able +to accept pairs of arguments, where the second member of each pair is optional. + +Analogous facilities would be needed for author-date and \lq\lq short form'' +citations. + +Incidentally, since abbreviations such as p., ch., sec., and fig.\ are +common when such divisions are specified, I think that citation commands +should arrange for the optional arguments to be typeset with +\verb+\frenchspacing+. + +\subsection{Details of reference-lists} + +\subsubsection{Variations within mainstream publishing practice} +\label{mainstream-lists} + +Although many academic and technical publications involve only a single +undivided reference-list, some such publications involve: +\begin{description} +\item[more than one list] + This situation can arise: + \begin{itemize} + \item when there is a list of \lq\lq further reading'' etc., + as well as the list of \lq\lq works cited''. + This case has been covered in sections \ref{support-additional}, + \ref{2.09-additional}, \ref{4-sets} and \ref{3.0-additional}. + \item when conference proceedings are produced, since each + contribution may have its own reference-list. + \item in manuals for software. For example, in \cite{norusis}, a + software house's own publications are introduced in the preface + and cited (in effect) using a \lq\lq short form'' scheme, while + other people's publications are listed at the end of the manual + and are cited using the author-date scheme. + \end{itemize} +\item[subdivisions within a list] + Some reference-lists, particularly in the humanities, are subdivided + according to the source of the cited documents (see + \cite[p.\ 183]{butcher-81}, \cite[p.\ 425]{chicago-82} and + \cite[p.\ 88]{gibaldi}). +\end{description} + +In some cases, an author may wish to add explanatory paragraphs describing, +for example, how material was chosen for a \lq\lq select bibliography'' +\cite[fig.\ 15.11]{chicago-82} or information about access to (document) +archives \cite[fig.\ 15.16]{chicago-82}. + +\subsubsection{\protect\LaTeX\ 2.09} + +\LaTeX\ 2.09 can cope with documents that have more than one +{\tt thebibliography} environment, and seems to deal satisfactorily +with a situation in which some \verb+\cite+ commands are to +one {\tt thebibliography} and some are to another (provided that +the {\it cite-key\/}s are unique). The default effect is +to give {\it label\/}s that are not unique, which will be acceptable +when each contribution to a \lq\lq conference proceedings'' has its +references numbered from one, but not if \lq\lq works cited'' +and \lq\lq additional references'' are both numbered from one +(see section \ref{2.09-additional}). + +The specification of {\tt thebibliography} \cite[p.\ 187]{lamport-86} +does not allow anything other than \verb+\bibitem+s within a +{\tt thebibliography} environment. Hence, it is not clear +how one can introduce subheadings within a reference-list. +(In practice, a \verb+\section*+ seems to work between +\verb+\bibitem+s, but I suspect that it puts \LaTeX\ 2.09 into a loop +if placed before the first \verb+\bibitem+.) + +Anyone trying to add explanatory paragraphs (as in \cite[fig.\ +15.11]{chicago-82} and \cite[fig.\ 15.16]{chicago-82}) will probably +find that \LaTeX\ 2.09 objects that +\begin{quote} +\lq\lq{\verb+Something's wrong--perhaps a missing \item+}''. +\end{quote} + +\subsubsection{\protect\LaTeX\ 3.0} + +Ideally, in order to provide support for the conventions that are routine +in mainstream publishing practice, \LaTeX\ 3.0 should be able to cope with +all the variations outlined in section \ref{mainstream-lists}. + +\paragraph{Multiple lists} + +The suggestions made in section \ref{what-to-do} would probably cater for most +situations where a document has more than one reference-list. + +The distinction between {\tt morerefs} and the other environments for +reference-lists would take care of situations where there is a list of +\lq\lq additional references'' as well as a list of \lq\lq works cited''. +The distinction between the \lq\lq short form'' commands/environment +and the other commands/environments would take care of situations where a +software house uses \lq\lq short form'' for its own publications +and some other scheme for other publications. Conference proceedings +will be able to have \lq\lq a reference-list for each contribution'' +if \LaTeX\ 3.0 follows the \LaTeX\ 2.09 precedent that allows +more than one {\tt thebibliography} in a document. + +\paragraph{Subdivisions and explanatory paragraphs} + +I have the impression that, because the sciences have different conventions +from the humanities, people using the \lq\lq reference by number'' citation +scheme are unlikely to want the options of subdividing their reference-list +and inserting explanatory paragraphs. Therefore, it would be legitimate to +say (for example) \lq\lq subdivisions and explanatory paragraphs are supported +within {\tt adrefs}, {\tt sfrefs} and {\tt morerefs} but not within +{\tt numrefs}'', if this made the programming task easier. + +For example, it might be convenient to implement {\tt numrefs} as +a \lq\lq list-making environment'' (as in \LaTeX\ 2.09) but to implement +the other environments in some other way. Lack of support for subdivisions +and explanatory paragraphs is unlikely to matter in {\tt numrefs}; the +\lq\lq other way'' (more like \verb+\paragraph+, perhaps?) might make it +easier to implement support for these facilities in the other environments. + +\paragraph{Other problems} +\label{reflist-scope} + +One approach to some of the problems mentioned in section \ref{2.09-other} +is for the standard styles to define the heading for the reference-list by, +for example, \verb+\def\numrefsheading{References}+, so that anyone who wants +to change the heading can do so by issuing a \verb+\renewcommand+ command +somewhere before the start of their reference-list. + +Another approach is to work in terms of the standard publishing industry +concept of \lq\lq back matter'' \cite[p.\ 4]{chicago-82}. Instead of having to +understand where the {\it heading}, {\it left-head}, {\it right-head} and +table-of-contents entry (or lack of it) originate for units such as the +glossary (if any), the reference-list(s) and the index (if any) +{\em separately}, an author would only have to understand how these features +are treated {\em consistently} within \lq\lq back matter''. + +Although the \lq\lq back matter'' approach could be used if environments +such as {\tt numrefs} followed the {\tt thebibliography} precedent and issued +commands such as \verb+\chapter+ or \verb+\section+ themselves, authors +might find the way that {\it heading}, {\it left-head}, {\it right-head} and +table-of-contents entry materialize less mysterious if it was just the same +for a reference-list as for (say) a glossary. This would imply that +{\tt numrefs}, {\tt adrefs}, {\tt sfrefs} and {\tt morerefs} should +not issue commands like \verb+\chapter+ or \verb+\section+ themselves. +As a bonus, it would then be possible for an author to insert an explanatory +paragraph before the reference-list, and to arrange for subdivisions. + +For example, if there was a {\tt backmatter} environment within which +\verb+\chapter+ was treated as defining a unit of \lq\lq back matter'', +an author's file might contain commands such as +\begin{verbatim} +\begin{backmatter} + \chapter{Glossary} + ... + \chapter{References} + \section{Primary sources} + \begin{sfrefs} + ... + \end{sfrefs} + \section{Secondary sources} + \begin{sfrefs} + ... + \end{sfrefs} + \chapter{Further reading} + \begin{morerefs} + ... + \end{morerefs} +\end{backmatter} +\end{verbatim} + +\subsection{Conclusion} + +\LaTeX\ has a large number of users, and potential users, who wish to produce +documents that conform to the conventions that are standard in academic +publishing. One element of their requirement is the need to conform to the +conventions for citations and reference-lists that are usual in their +disciplines. + +The choice for \LaTeX\ 3.0 may be between: +\begin{enumerate} +\item having more facilities for citations and reference-lists than + \LaTeX\ 2.09, perhaps as suggested in section \ref{what-to-do}. + This would imply an increase in: + \begin{itemize} + \item the amount of code needed to implement the facilities, and + the guru time needed for writing the code + \item the number of pages needed, in the successor to \cite{lamport-86}, + to describe the facilities --- perhaps 8 pages rather than + the 2 pages in \cite{lamport-86}. + \end{itemize} +\item no significant increase in the facilities provided for citations + and reference-lists. Contrary to the idea of \lq\lq freeing people + from formatting concerns to allow them to concentrate on writing'' + \cite[p.\ 8]{lamport-86}, many authors (perhaps most authors) would be + wasting time: + \begin{itemize} + \item hacking at style-files + \item searching (software) archives for ready made solutions + \item taking up support staff's time in the search for advice + (with the support staff + in turn taking up gurus' time in their search for solutions). + \end{itemize} + Moreover, most of this time would be wasted by (or on behalf of) authors + who don't want anything at all exotic; they just want to conform + to the conventions that are standard in traditional academic publishing. +\end{enumerate} +I'm inclined to think that the first option would be the lesser of the +two evils. + +\subsection*{Appendix: Interface with \protect\BibTeX} +\addcontentsline{toc}{subsection}{Appendix: Interface with \protect\BibTeX} + +The preceding sections make some suggestions for a \LaTeX\ 3.0 user +interface that would enable the do-it-yourself-er to conform to +the conventions that are usual in academic publishing. +It is also necessary to consider the implications for the interface to +\BibTeX. + +\subsubsection*{Single reference-list} + +Inspecting {\tt bst} files gives me the impression that, if it +was decided to adopt a scheme such as that described in section +\ref{what-to-do}, it would be fairly easy to produce new {\tt bst} files +to supersede existing ones. For example, a {\tt bst} file +that implemented a \lq\lq reference by number'' scheme would write +\verb+\numentry+ commands rather than \verb+\bibitem+ commands. + +If {\tt bst} files were created in this way, they would be able to +deal with the straightforward situation when there is a single +reference-list that contains all works cited (plus, possibly, +any works specified by a command like \verb+\nocite+). + +\subsubsection*{Multiple reference-lists, all with the same style} + +More complicated situations can arise in which a document involves +several reference-lists. For example: +\begin{itemize} +\item The editor of the proceedings of a conference might want the + published proceedings to have a reference-list at the end of each + chapter. +\item If, as suggested in section \ref{reflist-scope}, {\tt sfrefs} was + implemented in a way that allowed a sequence of {\tt sfrefs} environments + to each be preceded by a \verb+\section+ command, then, as far as + \BibTeX\ is concerned, each {\tt sfrefs} environment might be a separate + reference-list. +\end{itemize} + +In both these examples, the document would involve several reference-lists, +but each reference-list would need to be typeset in a common style. +I assume that the main problems would be in arranging: +\begin{itemize} +\item to have multiple {\tt bbl} files, or distinct divisions of a single + {\tt bbl} file +\item that each reference-list takes its entries from the correct {\tt bbl} + file, or from the correct division of a single {\tt bbl} file. +\end{itemize} + +\subsubsection*{Two reference-lists, each with a different style} + +People producing documents that have a second reference-list (e.g., +\lq\lq further reading'') in addition to the list of \lq\lq works cited'' +might want the first list typeset in one style and the second +list typeset in another. (In particular, if the \lq\lq reference by number'' +scheme is used, the first list will have \lq\lq labels'' but the second +list will have no \lq\lq labels''.) If the commands/environments suggested +in section \ref{what-to-do} were implemented, the first list would use +{\tt numrefs}, {\tt adrefs} or {\tt sfrefs}, while the second list would +use {\tt morerefs}. + +In this situation, it would be necessary to communicate to \BibTeX\ +that two lists are required, but that they are to be typeset in different +styles. Since the second list is to contain \lq\lq works {\em not\/} +cited'', it will also be necessary to specify the works to be shown in the +second list. + +If it is decided to extend the interface between \LaTeX\ and \BibTeX\ to +cater for such situations, it will probably be necessary to consider +defining alternatives to \LaTeX\ 2.09's \verb+\bibliography+ and +\verb+\bibliographystyle+ commands, since it seems unlikely that the syntax +of the \LaTeX\ 2.09 commands could be extended so as to pass the necessary +information. One might, for example, consider syntax such as +\verb+\bibtexcites[+{\it cites-style}\verb+]{+{\it bib-files}\verb+}+ +and +\verb+\bibtexmore[+{\it more-style}\verb+]{+{\it bib-files}\verb+}{+{\it + key-list}\verb+}+. +Here, it is assumed that: +\begin{itemize} +\item the \verb+\documentstyle+ would set defaults for the {\it cites-style} + and {\it more-style} that are to be passed to \BibTeX, but the user + can over-ride the defaults via the optional arguments to + \verb+\bibtexcites+ and \verb+\bibtexmore+ +\item \verb+\bibtexmore+'s {\it key-list} argument would be used to + specify the works to be included in the list of \lq\lq additional + references''. +\end{itemize} + +If it is not practicable to extend the \LaTeX/\BibTeX\ interface to cater for +these situations automatically, it would presumably be a matter of +some \lq\lq human intervention'': +\begin{itemize} +\item to prepare a {\tt bbl} file for the \lq\lq additional references'' +\item to \verb+\input+ the {\tt bbl} file. +\end{itemize} + +\section{Further e-mail comments} + +\begin{footnotesize}\begin{verbatim} +From: David Rhead ... +Date: 4 Apr 91 12:16:14 + +Here are a few comments on Nico's comments (5th March) about my paper on +citations and reference-lists. + + +>> 2. The paper on reference lists concentrates too much on layout and not +>> enough on structure. For a, in my humble opinion, much more valuable +>> discussion of LaTeX 3.0, reference lists and BibTeX I'd like to refer to the +>> talk Frank Mittelbach gave at the Cork conference last year. + +Frank has sent me a copy of "BibTeX reconsidered", by Reinhard Wonneberger +and himself. I think that this is the written version of the talk that +he gave at Cork. There seems to be a lot of common ground between my paper +and "BibTeX reconsidered", although the former is looking at it from the LaTeX +point-of-view while the latter is looking at it from the BibTeX point-of-view. +[Both my paper and "BibTeX reconsidered" would like support for multiple +bibliographies, the short title/form scheme (often in footnotes) and +commented bibliographies.] + +I'd like "document support" (as Reinhard/Frank put it) for reference-by-number, +author-date and short-form citation schemes. My paper suggested one possible +user interface through which this support could be provided. Of course, +other interfaces could be defined that would do the job. I think that the +main thing is to provide satisfactory support for the 3 schemes. + + +>> I'm totally opposed to the idea of having different coding schemes for +>> different systems of citation. In my opinion, this goes completely against +>> the basic idea behind LaTeX and SGML, namely separation of form and contents. +>> Consider the amount of re-coding when switching from the number system to the +>> name-year system! + +There are differences between the schemes that may be so significant that +they could/should be regarded as "different in form". +* For instance, ISO 690 gives the example + The notion of an invisible college has been explored in the + sciences (24). Its absence among historians is noted by + Steig (13, p. 556). It may be as Burchard (8) points out ... + which, if converted to author-date, would be + The notion of an invisible college has been explored in the + sciences (Crane, 1972). Its absence among historians is noted by + Steig (1981, p. 556). It may be as Burchard (1965) points out ... + where the substitution has to take account of whether the author's name + does or does not occur naturally in the sentence. I.e. the form of + citation depends on what else is in the sentence, and conversion + cannot easily be automated. Similarly, I'd be surprised if one can + guarantee to be able to change from other schemes to the + short-form scheme without some re-writing. +* Reference-by-number involves keeping track of one thing (the number), + author-date involves keeping track of two (surname and date), short-form + involves keeping track of at least two things (form for first citation, + form for subsequent citations, perhaps also the full form as the default + form for first citation). +If the schemes are different in form (i.e. involve different logical +structures), it may be legitimate to consider having different coding +schemes, while still aiming at separation of form from content (e.g. +whether reference-by-number uses superscripts or brackets). + +However, if someone has sufficient insight to be able to propose a single user +interface that can cater for all three schemes (plus possible "additional +references") within one set of commands/environments, I agree that it +would be very nice. My own attempts to define a single interface +that would cater for all three schemes have ended up being unsatisfactory. +Here's how they end up unsatisfactory. + ------------ +For the purpose of this account I'll use \refentry to mean the successor +to \bibitem. Presumably \refentry would have to have 2 or 3 arguments besides +the cite-key (rather than \bibitem's one extra argument) so that the arguments +could be used for: +- nothing, in the reference-by-number scheme (since LaTeX would supply + the numbers) +- author and date, in the author-date scheme +- first-citation-form and subsequent-citation-form, for the short-form + scheme. +Thus, for reference-by-number, the user (or BibTeX) would supply +\refentry{cite-key}{}{} ... +but for author-date they would supply +\refentry{cite-key}{author}{date} ... +while for short form they would supply +\refentry{cite-key}{fairly-full-form}{short-form} ... +[We're already in trouble. How do we deal with what appears to be the tendency +in short form for the "full reference" to be the default "fairly full form"? +Do we go for \refentry{cite-key}[fairly-full-form]{short-form}{full reference}, +and if so what are the implications for the other 2 schemes?] +Or should one go for +\refentry{cite-key}{author}{date}{fairly-full-form}{short-form} ... +so as to give LaTeX all the information it needs to allow completely +automatic switching between citation schemes, separating form from content +but placing a heavy burden on the user (who would have to provide +at least dummy information for both author-date and short-form +schemes, even if they are only going to use reference-by-number)? + +For citation commands one might have \cite and \shortcite (following +precedents in the archives) [but see section 6.5 of my paper, about citation +of a specific devision]. By aiming at author-date, one might be able to +get a .tex file that also worked for reference-by-number. For example, +if \cite and \shortcite both gave a number when a .sty file implemented +reference-by-number, while \cite gave (author, date) and \shortcite +gave (date) when a .sty file implemented author-date, the following +input might work for both schemes: + The notion of an invisible college has been explored in the + sciences \cite{crane-72}. Its absence among historians is noted by + Steig \shortcite{steig-81[p. 556]}. It may be as Burchard + \shortcite{burchard-65} points out ... +I don't think that the reverse would work, i.e. if you think in terms +of reference-by-number while writing, you'll do things like + Steig \cite{steig-81[p. 556]}. It may be as Burchard +which, if converted automatically to author-date, would give + Steig (Steig, 1981; p. 556). It may be as Burchard +which gives two occurences of Steig, which isn't right. +For short-form, you might interpret \cite as meaning "the form of citation +used at first citation" and \shortcite as meaning "the form to be used +subsequently". But if you do this, you'll put your \shortcites in +places that are different from the places you'd put them for author-date +For example, you might have (using an ISO 690 example again) + ... Steig \cite{steig-81}. It may be as Burchard + \cite{burchard-65} points out ... Steig \shortcite{steig-81} + has further noted ... +for the MLA or + ... Steig\footnote{\cite{steig-81}} ... Steig\footnote{\shortcite{steig-81}} +for most other publications that use short-form. [This assumes that the first +of these citations of Steig above is actually the first citation of Steig +in the whole document (or chapter).] But this would not give you the right +input file for author-date, for which you would want + ... Steig \shortcite{steig-81}. It may be as Burchard +Again, you might be able to convert automatically TO reference-by-number, +but it seems unlikely that you could convert automatically FROM +reference-by-number. The problem might disappear if LaTeX itself could work +out which citations are "first citations". Then someone can put \cites and +\shortcites in the places required for author-date but choose a .sty file +that gives short-form; the .sty file would ignore the distinction between +\cite and \shortcite and would use the fairly-full-form for "first citation" +and the short-form for subsequent citations. But can LaTeX work out which +citations are "first citations"? + ------------ +Although one can try (as above) to imagine a single set of +commands/environments that would support all three schemes, it seems to +lead to problems, and I worry that, in making things right for one scheme, +they'll be made wrong for another. So I gave up on the idea of a single +set of commands, which was why my paper went for the idea of separate +commands/environments tailored to the 3 specific citation schemes. +But, if someone has more success than I did in imagining how a single set of +commands/environments could be simultaneously compatible with all three schemes, +I'd be interested to see their proposals. + +Or should one be less ambitions, perhaps aiming to satisfy people who +want reference-by-number and author-date, and not bothering about people +who want short-form? Things like \refentry{cite-key}{author}{date}, +\cite and \shortcite might work for both reference-by-number and author-date. +(People who want reference-by-number would have to supply author and date +information that they might regard as redundant, unless they go +\refentry{cite-key}{}{} or the syntax is something like +\refentry{cite-key}[author][date].) + + +>> To David's review I'd like to add that \bibitem's have no sub-division, at +>> least not one that is indicated by explicit control sequences (`tags'). +>> Instead, the tagging of \bibitem's is done _outside_ LaTeX, which has always +>> struck me as odd. + +In theory, it would be nice if the \bibitem's did have subdivisions. There +might be subdivisions for the do-it-yourself-er that were analogous to +the fields used by the BibTeX-er. + +In practice, to sub-divide the \bibitems would involve deciding what the +subdivisions should be, which leads one into questions that cause difficulty +in BibTeX (e.g., "Should it be address or place-of-publication?", +"Is it really worth having booklet separate?", "Is it really worth +having phdthesis separate from mastersthesis?", "Does volume mean +number-in-series or subdivision-of-book?"). It may not be easy to +answer these questions. I don't think that it is worth delaying +LaTeX 3.0 while answers are sought. [One could always return to the +question for LaTeX 4.0, if there was one!] +\end{verbatim}\end{footnotesize} + + -- cgit v1.2.3