General ⇒ Same Authors published in same Year

[someshpr]

The journal I am trying to conform my article for does not provide a LaTeX template. But it says this:

All styles should be based on The Chicago Manual of Style.
References in the text should be quoted in the form AuthorLastName (year), Author1LastName and Author2LastName (year), or if there are three or more authors, Author1LastName et al. (year). The list of references should be given at the end of the text, in alphabetical order (each author's surname first, with all authors listed).

So I am using natbib package and chicago bibliography style. Now I want to cite three papers by same first author but different coauthors (all have three authors in total) all published in the same year. This gives me an error.

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multiple citation on page 1: same authors and year(natbib) without
distinguishing extra letter, (natbib) appears as question mark.

and the output looks like:

[Roy et al., 2005a,b,?]

I can manually edit the bbl file to rectify this, but is there any other way to do it?

I am attaching the working example of this (.tex and .bib files along with the output PDF file). I am using PDFLaTeX in Kile with a TeX Live distribution.

Please let me know if any more information is needed.

TIA,
Somesh

[Mickle]

I'm have a similar problem with natbib and the chicago style. I get this output warning

Code: Select all

Package natbib Warning: Multiple citation on page 1: same authors and
                        year without distinguishing extra letter, appears
                        as question mark.

This is the concerned MWE.

Code: Select all

\documentclass[letterpaper,11pt]{article}
\usepackage[square]{natbib}

\begin{document}
\section{Introduction}

This should work\citep{luo2009a, luo2009b}

\bibliographystyle{chicago}
\bibliography{bug}

\end{document}

And here is a sample database file.

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@INPROCEEDINGS{Luo2009a,
  author = {Luo, Y. and Szidarovszky, F. and Al-Nashif, Y. and Hariri, S.},
  title = {A game theory based risk and impact analysis method for Intrusion Defense Systems},
  booktitle = {2009 IEEE/ACS International Conference on Computer Systems and Applications (AICCSA)},
  year = {{2009}},
  pages = {975--982},
  organization = {IEEE}
}

@INPROCEEDINGS{Luo2009b,
  author = {Luo, Y. and Al-Nashif, Y. and Szidarovszky, F. and Hariri, S.},
  title = {Game Tree Based Partially Observable Stochastic Game Model for Intrusion Defense Systems (IDS)},
  booktitle = {IIE Annual Conference and EXPO (IERC 2009)},
  year = {{2009}},
  address = {Miami, Florida, USA},
  month = {may 30-june 3}
}

I was expecting the output to be: "This should work[Luo et al., 2009a, 2009b]." However, I got: "This should work[Luo et al., 2009, ?]."

I am using the latest version of MiKTeX as of Aug 27 2013. There are no updates provided via MiKTeX currently. I am compiling with PDFLaTeX straight to a PDF.

I know it is possible to edit the .bbl file, but that feels wonky. Is this a bug in the chicago style? I am I doing something wrong? Is there an additional package I need to include? Is there an update/patch somewhere to fix this?

Thanks in advance for any help.