# Problem with too verbose generated citations

In the following MWE, bibtex generates different output for \citep{}, depending on which citations are used and which are not. I assume that the problem is related to breaking ambiguity since the two authors with last name Li have different given names.

In the case of only using \citep{} once with Li2009 or Li2009a, I get a citation (Li et al., 2009), when using both, I get (Li, Handsaker, Wysoker, Fennell, Ruan, Homer, Marth, Abecasis & Durbin 2009) (Li, Yu, Li, Lam, Yiu, Kristiansen & Wang 2009).

Is there any way to make the citation less verbose? I realize that there has to be some way to discriminate different authors with the same last name, but is there another one? Like using the second author only?

\documentclass{article}

\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@article{Li2009,
Publisher = {{Oxford Univ Press}},
author = {Li, Heng and Handsaker, Bob and Wysoker, Alec and Fennell, Tim and Ruan, Jue and Homer, Nils and Marth, Gabor and Abecasis, Goncalo and Durbin, Richard},
title = {{The sequence alignment/map format and SAMtools}},
journal = {{Bioinformatics}},
volume = {25},
number = {16},
pages = {2078-2079},
year = {2009}
}

@article{Li2009a,
Publisher = {{Oxford Univ Press}},
author = {Li, Ruiqiang and Yu, Chang and Li, Yingrui and Lam, Tak-Wah and Yiu, Siu-Ming and Kristiansen, Karsten and Wang, Jun},
title = {{SOAP2: an improved ultrafast tool for short read alignment}},
journal = {{Bioinformatics}},
volume = {25},
number = {15},
pages = {1966-1967},
year = {2009}
}
\end{filecontents}

\usepackage[sort]{natbib}

\begin{document}

\citep{Li2009}
\citep{Li2009a}

\bibliographystyle{agsm}
\bibliography{\jobname} % no file ending necessary

\end{document}

• Not a solution but a suggestion: biblatex doesn't have this problem. Simply import the package with option style=authoryear', add \addbibresource{\jobname.bib} to the preamble, change your \citep commands to \parencite, add \printbibliography at the end, and Bob's your uncle. I don't know the bibliographystyle agsm, so you'd have to find an equivalent for that. – user10274 Aug 14 '14 at 8:37
• My impression is that agsm.bst doesn't allow short citations. – egreg Aug 14 '14 at 9:56

Try \bibliographystyle{APA} to see the difference.
If you are required to take agsm then there might be a way to edit the respective .bst file, but thats beyond my skills :)`