# ACM Bibliography Style Natbib Error: 'Author undefined for citation'

I was writing an academic paper and the following method of citing an author was working until I had to switch to the acm bibliography style and I started getting the following error:

Package natbib Warning: Author undefined for citation 'bib01'


This is the MWE:

testTex.tex

\documentclass{journal}
\bibliographystyle{acm}

\usepackage[numbers]{natbib}

\begin{document}

\citeauthor{bib01}

\bibliography{testBib}

\end{document}


testBib.bib

@article{bib01,
author = {Author},
title = {Bib Item},
booktitle = {Bib Book},
publisher = {Foo Publishing},
year = {2013},
pages = {75-88}
}


Using:

Texmaker 4.0

MiKTeX-TeX 2.9.3759 (3.1415926) (MiKTeX 2.9)

The documentation of the natbib package states that the commands \citeauthor and \citeyear are available only if an authoryear-style citation style is in effect. The acm bibliography style, however, seems to use a purely numeric citation style, and you're loading the natbib package with the option numbers. Thus, you can't use the \citeauthor along with the acm bibliography style.
• So is there a way to cite author under acm bib style then? – Xin Aug 19 '16 at 21:27
• @Xin - The acm bibliography style can only generate purely-numeric citation call-outs. Unfortunately for you, it cannot generate author-number citaton call-outs. – Mico Aug 22 '16 at 14:30