# Problem with acmsmall citations

I have a problem using the acmsmall package (which can be found here), which can be reproduced with the following MWE.

test.tex

\documentclass{acmsmall}
\begin{document}
\cite{a,b}
\bibliography{test}
\bibliographystyle{acmsmall}
\end{document}


test.bib

@inproceedings{a,
author = {Surname1, Name1 and Surname2, Name2 and Surname3, Name3},
booktitle = {{BookA}},
pages = {1--2},
title = {{TitleA}},
year = {2015}
}

@inproceedings{b,
author = {Surname1, Name1 and Surname4, Name4 and Surname3, Name3},
booktitle = {{BookB}},
pages = {1--2},
title = {{TitleB}},
year = {2015}
}


This code produces this output:

Even though author lists are different, they are both cited as "Surname1 et al." in the text and they seem to be the same reference. Of course it would be much better to have "2015a" and "2015b", but it seems this is done only if all the authors are the same. Manually modifying the year to "2015a" and "2015b" in the bibtex file does not work (it seems that the bibtex style automatically keeps the last 4 characters of the year entry, hence they would appear as "015a" and "015b"). Any idea?

• Can you add a pointer where the class and bst can be found? – egreg Mar 23 '15 at 21:47
• Yes, you are right, done. – Filippo Bistaffa Mar 23 '15 at 21:54
• I'm afraid the bib style is quite dumb and doesn't distinguish between these cases. :( – egreg Mar 23 '15 at 22:04

The style acmsmall.bst is not an official style of ACM and is not supported. I have been working with ACM on their LaTeX and BibTeX styles, and this is the first time I see this file.
The official .bst files can be found there: http://www.acm.org/publications/latex_style. I've just compiled your example with the line \bibliographystyle{ACM-Reference-Format-Journals}, and got [Surname1 et al. 2015a; Surname1 et al. 2015b], as it should be.