\documentclass[12pt]{iopart} \bibliographystyle{iopart-num} \begin{document} \title{Test document for iopart-num with the iopart document class} \author{M~A~Caprio} \address{Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, Connecticut 06520-8120, USA} \begin{abstract} This file may be used to test the iopart-num BibTeX style. \end{abstract} \section{Introduction} This file may be used to test the iopart-num BibTeX style. This version of the file is for use with the iopart document class. \nocite{*} \section*{References} \bibliography{iopart-num-example} \end{document}