# Two papers that abbreviate to the same Author et al (1999) in text

I have two citations like

@ARTICLE{Openshaw1999a,
author = {Openshaw, S. and Turton, I. and Macgill, J},
title = {Using the Geographical Analysis Machine to Analyze Limiting Long-term
Illness},
journal = {Geographical and Environmental Modelling},
year = {1999},
volume = {3.1},
pages = {83-99},
owner = {ijt1},
timestamp = {2010.09.27}
}


and

@INCOLLECTION{citeulike:8468480,
author = {Openshaw, Stan and Turton, Ian and Macgill, James and Davy, John},
title = {{Putting the Geographical Analysis Machine on the Internet}},
booktitle = {Innovations in GIS 6},
publisher = {Taylor and Francis},
year = {1999},
editor = {Gittings, Bruce},
chapter = {10},
pages = {121--132},


which both appear in the text as “Openshaw et al (1999)” when I cite them. Other than using [fullnamesfirst] as an option to natbib is there a way to prevent them appearing to be citations of the same paper?

-
to clarify I'm trying to avoid using the full citation as this is an abstract and space is limited so I'd like to get Openshaw et al (1999a) and later (1999b). –  iant Jan 19 '11 at 21:30
This should be the default with natbib style such as plainnat or abbrvnat. What bibliography style are you using? –  Olof Jan 19 '11 at 23:30
I was using chicago but on switching to apalike it does work as I'd expect. –  iant Jan 19 '11 at 23:58

Citing the two papers as "Openshaw et al (1999a)" and "Openshaw et al (1999b)" implies that those papers were written by the same co-authors, while in fact one author (John Davy) was part of the second, but not of the first author team. (Herbert's use of the alpha style avoids this problem.) Using author-year-styles, I would cite the papers as "Openshaw, Turton et al (1999)" and "Openshaw, Turton, Macgill et al (1999)". I'm not aware of a bibliography style that will do so automatically (disambiguation of author lists is on the roadmap for future versions of biblatex). Using natbib, you could define

\defcitealias{key1}{Oppenshaw, Turton et al (1999)}
\defcitealias{key2}{Oppenshaw, Turton, Macgill et al (1999)}


and write

\citetalias{key1,key2}


in the text, but this solution is far from perfect (\citepalias would result in double parentheses).

UPDATE: Disambiguation of author names and name lists was implemented in biblatex v1.4, released on March 31st, 2011. See section 4.11.4 of the biblatex manual for details. Have a look at the following example with the package option uniquelist=true:

\documentclass{article}

\usepackage[style=authoryear,maxnames=1,uniquelist=true]{biblatex}

\usepackage{filecontents}

\begin{filecontents}{\jobname.bib}
@article{Openshaw1999a,
author = {Openshaw, Stan and Turton, Ian and Macgill, James},
title = {Using the Geographical Analysis Machine to Analyze Limiting Long-term Illness},
journaltitle = {Geographical and Environmental Modelling},
year = {1999},
volume = {3.1},
pages = {83-99},
owner = {ijt1},
timestamp = {2010.09.27},
}
@incollection{citeulike:8468480,
author = {Openshaw, Stan and Turton, Ian and Macgill, James and Davy, John},
title = {{Putting the Geographical Analysis Machine on the Internet}},
booktitle = {Innovations in GIS 6},
publisher = {Taylor and Francis},
year = {1999},
editor = {Gittings, Bruce},
chapter = {10},
pages = {121--132},
location = {London},
}
\end{filecontents}

\nocite{*}

\begin{document}

\printbibliography

\end{document}


For comparison see the output of the same example with uniquelist=false:

-

biblatex can do some of what you want. In fact, it will automatically add 1999a or 1999b with the style=authoryear style. This will not, however, deal with the problem lockstep mentioned: viz, the disambiguation of author lists. You could set the maxnames=4 option, and this would disambiguate the author lists, but that's probably suboptimal...

-

use the star version

foo~\citep*{Openshaw1999a,citeulike:8468480}


-
The two citations appear in different paragraphs and I'm using author-year citations –  iant Jan 19 '11 at 21:26
@iant: use \citeyear then and \bibliographystyle{abbrvnat} –  Herbert Jan 19 '11 at 21:40