# biblatex same first author same year: cite as “a”, “b” etc

In the below file, I wanted the three references to be cited as Inger et al 2006a, Inger et al 2006b and Inger et al 2006c. Can I achieve this using biblatex? If not, can I make alterations to my .bib file that will achieve this?

\documentclass{article}

\usepackage[style=authoryear-comp, maxcitenames=2, maxbibnames=50]{biblatex}

\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@article{IngerEtAl2006a,
title={Using daily ration models and stable isotope analysis to predict biomass depletion by herbivores},
author={Inger, Richard and Ruxton, Graeme D and Newton, Jason and Colhoun, Kendrew and Mackie, Kerry and Robinson, James A and Bearhop, Stuart},
journal={Journal of Applied Ecology},
volume={43},
number={5},
pages={1022--1030},
year={2006},
publisher={Wiley Online Library},
tag={}
}
@article{IngerEtAl2006b,
title={Prey choice affects the trade-off balance between predation and starvation in an avian herbivore},
author={Inger, Richard and Bearhop, Stuart and Robinson, James A and Ruxton, Graeme},
journal={Animal Behaviour},
volume={71},
number={7},
pages={1335--1341},
year={2006},
publisher={Elsevier}
}
@article{IngerEtAl2006c,
title={Temporal and intrapopulation variation in prey choice of wintering geese determined by stable isotope analysis},
author={Inger, Richard and Ruxton, Graeme D and Newton, Jason and Colhoun, Kendrew and Robinson, James A and Jackson, Andrew L and Bearhop, Stuart},
journal={Journal of Animal Ecology},
volume={75},
number={5},
pages={1190--1200},
year={2006},
publisher={Wiley Online Library}
}
\end{filecontents}
\begin{document}

\cite{IngerEtAl2006a}\\\\
\cite{IngerEtAl2006b}\\\\
\cite{IngerEtAl2006c}

\printbibliography

\end{document}

• Maybe uniquelist=false helps? - It seems to do what you want though the sorting might not be entirely to your liking. IngerEtAl2006a got a "b" and IngerEtAl2006b an "a" here, but that can be adjusted via sortyear if you insist. – moewe Jun 20 '15 at 19:00
• Thanks but I would prefer a,b,c in the .bib file to match a,b,c in the PDF. What exactly do you mean by "adjusted via sortyear"? I tried sorting=nyt but this didn't solve problem – luciano Jun 20 '15 at 19:15
• For a similar problem and discussion see biblatex keys inside editor are not equal to printed bib keys. The problem is that since the works are strictly speaking by different authors, biblatex does not want to sort the entries as belonging to the same author in the bibliography, unless you also specify sortname = {Inger, Richard} for all entries. You would then also add sortyear = {2006-1} for the a entry, sortyear = {2006-2} for b and finally sortyear = {2006-3} for c all in your .bib file to get the desired sorting. – moewe Jun 20 '15 at 19:35
• – Johannes_B Jun 21 '15 at 13:02

If you want all of the citations to be "Inger et al.", you will need to set uniquename=false.

This will not solve the sorting problem since still for biblatex all three articles were written by a different set of authors, and the bibliography is sorted first and foremost by authors. Because Mr Bearhop is second author in IngerEtAl2006b that paper comes before the two others which have Mr Ruxton as second author when sorting.

You can now do two things.

You could make your bibliography display only a maximum of two names as well, as in

\usepackage[style=authoryear-comp, maxnames=2, uniquelist=false]{biblatex}


Of course then all citations are sorted under "Inger, Richard et al." and then the title is consulted to sort the entries.

Alternatively, you can force biblatex to sort all entries under "Inger, Richard et al." by adding

sortname = {Inger, Richard and others},


to the entries.

In any case, now the citations will all be sorted as if "Inger, Richard et al." was the author.

Now the order still is not right since the alphabetic order of the titles does not coincide with your order, so we can add the sortyear field as follows (this is how it would look like if you also add sortname, see the MWEs below for more)

@article{IngerEtAl2006a,
title={Using daily ration models and stable isotope analysis to predict biomass depletion by herbivores},
author={Inger, Richard and Ruxton, Graeme D and Newton, Jason and Colhoun, Kendrew and Mackie, Kerry and Robinson, James A and Bearhop, Stuart},
journal={Journal of Applied Ecology},
volume={43},
number={5},
pages={1022--1030},
year={2006},
publisher={Wiley Online Library},
sortyear = {2006-1},
sortname = {Inger, Richard and others},
}
@article{IngerEtAl2006b,
title={Prey choice affects the trade-off balance between predation and starvation in an avian herbivore},
author={Inger, Richard and Bearhop, Stuart and Robinson, James A and Ruxton, Graeme},
journal={Animal Behaviour},
volume={71},
number={7},
pages={1335--1341},
year={2006},
sortyear = {2006-2},
sortname = {Inger, Richard and others},
publisher={Elsevier}
}
@article{IngerEtAl2006c,
title={Temporal and intrapopulation variation in prey choice of wintering geese determined by stable isotope analysis},
author={Inger, Richard and Ruxton, Graeme D and Newton, Jason and Colhoun, Kendrew and Robinson, James A and Jackson, Andrew L and Bearhop, Stuart},
journal={Journal of Animal Ecology},
volume={75},
number={5},
pages={1190--1200},
sortyear = {2006-3},
sortname = {Inger, Richard and others},
year={2006},
publisher={Wiley Online Library}
}


Where the a entry gets sortyear = {2006-1}, the b entry sortyear = {2006-2} and c sortyear = {2006-3}. For another example of the sortyear field have a look at the knuth:ct entries in biblatex-examples.bib.

MWE for sortname

\documentclass{article}
\usepackage[style=authoryear-comp,
maxcitenames=2, maxbibnames=999,
uniquelist=false, uniquename=false]{biblatex}

\usepackage{filecontents}
\begin{filecontents*}{\jobname.bib}
@article{IngerEtAl2006a,
title={Using daily ration models and stable isotope analysis to predict biomass depletion by herbivores},
author={Inger, Richard and Ruxton, Graeme D and Newton, Jason and Colhoun, Kendrew and Mackie, Kerry and Robinson, James A and Bearhop, Stuart},
journal={Journal of Applied Ecology},
volume={43},
number={5},
pages={1022--1030},
year={2006},
publisher={Wiley Online Library},
sortyear = {2006-1},
sortname = {Inger, Richard and others},
}
@article{IngerEtAl2006b,
title={Prey choice affects the trade-off balance between predation and starvation in an avian herbivore},
author={Inger, Richard and Bearhop, Stuart and Robinson, James A and Ruxton, Graeme},
journal={Animal Behaviour},
volume={71},
number={7},
pages={1335--1341},
year={2006},
sortyear = {2006-2},
sortname = {Inger, Richard and others},
publisher={Elsevier}
}
@article{IngerEtAl2006c,
title={Temporal and intrapopulation variation in prey choice of wintering geese determined by stable isotope analysis},
author={Inger, Richard and Ruxton, Graeme D and Newton, Jason and Colhoun, Kendrew and Robinson, James A and Jackson, Andrew L and Bearhop, Stuart},
journal={Journal of Animal Ecology},
volume={75},
number={5},
pages={1190--1200},
sortyear = {2006-3},
sortname = {Inger, Richard and others},
year={2006},
publisher={Wiley Online Library}
}
\end{filecontents*}
\begin{document}
One \cite{IngerEtAl2006a}, Two \cite{IngerEtAl2006b}, Three \cite{IngerEtAl2006c}.

\printbibliography
\end{document}


Note how the sorting by names is severely messed up here.

MWE for maxnames=2

\documentclass{article}
\usepackage[style=authoryear-comp,
maxnames=2,
uniquelist=false, uniquename=false]{biblatex}

\usepackage{filecontents}
\begin{filecontents*}{\jobname.bib}
@article{IngerEtAl2006a,
title={Using daily ration models and stable isotope analysis to predict biomass depletion by herbivores},
author={Inger, Richard and Ruxton, Graeme D and Newton, Jason and Colhoun, Kendrew and Mackie, Kerry and Robinson, James A and Bearhop, Stuart},
journal={Journal of Applied Ecology},
volume={43},
number={5},
pages={1022--1030},
year={2006},
publisher={Wiley Online Library},
sortyear = {2006-1},
}
@article{IngerEtAl2006b,
title={Prey choice affects the trade-off balance between predation and starvation in an avian herbivore},
author={Inger, Richard and Bearhop, Stuart and Robinson, James A and Ruxton, Graeme},
journal={Animal Behaviour},
volume={71},
number={7},
pages={1335--1341},
year={2006},
sortyear = {2006-2},
publisher={Elsevier}
}
@article{IngerEtAl2006c,
title={Temporal and intrapopulation variation in prey choice of wintering geese determined by stable isotope analysis},
author={Inger, Richard and Ruxton, Graeme D and Newton, Jason and Colhoun, Kendrew and Robinson, James A and Jackson, Andrew L and Bearhop, Stuart},
journal={Journal of Animal Ecology},
volume={75},
number={5},
pages={1190--1200},
sortyear = {2006-3},
year={2006},
publisher={Wiley Online Library}
}
\end{filecontents*}
\begin{document}
One \cite{IngerEtAl2006a}, Two \cite{IngerEtAl2006b}, Three \cite{IngerEtAl2006c}.

\printbibliography
\end{document}


Note how the sorting makes slightly more sense here, but of course at the expense of dropping all co-authors.

• The best solution is of course to let biblatex do all of its stuff and not tinker with the sorting too much. The first step is to stop using bibkeys with a, b, c etc. or at least to not expect biblatex to match its disambiguation letters with yours. – moewe Jun 21 '15 at 17:38
• that's such a helpful answer you've given above. But after all that , I think the solution is indeed to stop using a, b, c in keys – luciano Jun 23 '15 at 15:12
• @luciano I'm glad you liked the answer, and it is even nicer for me to know that the answer got you on the right (in my eyes at least) way of not using a, b, c in bibkeys - or at least not expecting the letters to be reflected in the actual document. – moewe Jun 23 '15 at 17:36