BibTeX, biblatex and biber ⇒ natbib - Multiple citation without distinguishing letter?!

[velocidex]

Hi all,

I am having a problem with bibtex & natbib, when I have two references that have the same author and year. I understand that you need to put a distinguishing letter after the year so that bibtex knows how to distinguish between them. However, I have only seen examples which do this for .bbl files, whereas I want this to happen from my .bib file.

Here is my bibtex file:

Code: Select all

@ARTICLE{Berengut04a,
   author = {{Berengut}, J.~C. and {Dzuba}, V.~A. and {Flambaum}, V.~V. and 
	{Kozlov}, M.~G. and {Marchenko}, M.~V. and {Murphy}, M.~T. and 
	{Webb}, J.~K.},
    title = "{Laboratory spectroscopy and the search for space-time variation of the fine structure constant using QSO spectra}",
  journal = {unpublished, arXiv:physics/0408017},
   eprint = {arXiv:physics/0408017},
 keywords = {Physics - Atomic Physics},
     year = 2004a,
    month = aug,
   adsurl = {http://adsabs.harvard.edu/abs/2004physics...8017B},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

@ARTICLE{Berengut04b,
   author = {{Berengut}, J.~C. and {Dzuba}, V.~A. and {Flambaum}, V.~V. and 
	{Marchenko}, M.~V.},
    title = "{{$\alpha$}  dependence of transition frequencies for some ions of Ti, Mn, Na, C, and O and the search for variation of the fine-structure constant}",
  journal = "Phys. Rev. A",
   eprint = {arXiv:physics/0404008},
 keywords = {Determination of fundamental constants, Relativistic and quantum electrodynamic effects in atoms and molecules, Atomic processes and interactions},
     year = 2004b,
    month = dec,
   volume = 70,
   number = 6,
    pages = {064101-+},
      doi = {10.1103/PhysRevA.70.064101},
   adsurl = {http://adsabs.harvard.edu/abs/2004PhRvA..70f4101B},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

And here is a minimal working example:

Code: Select all

\documentclass[useAMS,usenatbib]{mn2e}

\title[test]{test}

\author[author]{author
}

\begin{document}

\date{Accepted ---. Received ---; in original form ---}

\pagerange{\pageref{firstpage}--\pageref{lastpage}} \pubyear{2006}

\maketitle

\label{firstpage}

\begin{abstract}
test
\end{abstract}

\begin{keywords}
keywords
\end{keywords}

    Some authors: \citet{Berengut04a,Berengut04b}.
    
\bibliography{problem}
\bibliographystyle{mn2e}


\label{lastpage}

\end{document}

.

This requires the mn2e .cls and .bst files, available from http://www.wiley.com/bw/static/mnras_latex.asp

During compiliation, I get the following warning:

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

The key part is the Berengut citation, which gives Berengut (2004, ?) instead of the desired Berengut (2004a, b) etc.

I don't want to move to doing this by hand in the .bbl file. Can someone please advise me of the changes I need to make to my tex or .bib file to get this working?

Many thanks!

[josephwright]

There seem to be a couple of things going on. First, in your .bib file you should just include the year, and not try to add the "a", "b", etc. yourself. However, making that change does not solve the problem here. If you try your demo with one of the standard natbib styles then all is well (say trying unsrtnat). That suggests that the .bst file the journal have provided is defective. I notice that it seems to be very old, and natbib has been updated a lot since the .bst file was written. That's a problem: I guess you could try to fix the .bst file but this may not be trivial!

[TexUser123]

To me this problem occured while using \usepackage{natbib}, but another style (chicago.bst).
\usepackage{chicago} solved this for chicago style at least. Maybe there are some inconsistencies between them and you had a similar case...