# [Tex/LaTex] Natbib+harvard.bst: papers in same year listed in the wrong order

bibtexnatbibsorting

I have a bibliography in which a particular author wrote two papers in the same year. Bibtex is sorting them alphabetically by title, but I want them listed chronologically. (So in the example below 'universal grammar' should precede 'English as a formal language'.) What's the appropriate way to flip the order?

MWE:

\documentclass{article}
\usepackage{natbib}
\begin{document}

... formal semantics in the  Montagovian tradition \citep{montague1970aug,montague1970befl,montague1973ptq}.

\bibliographystyle{harvard}
\bibliography{test}
\end{document}


This generates the text 'formal semantics in the Montagovian tradition (Montague, 1970b,a, 1973)' whereas I actually want '1970a,b,1973'.

test.bib file for MWE:

@incollection{montague1973ptq,
title={The proper treatment of quantification in ordinary {English}},
author={Montague, Richard},
booktitle={Approaches to natural language},
editor={Hintikka, K. Jaakko J. and Moravcsik, Julius M.E. and Suppes, Patrick},
pages={221--242},
year={1973},
publisher={Dordrecht}
}

@article{montague1970aug,
title={Universal grammar},
author={Montague, Richard},
journal={Theoria},
volume={36},
number={3},
pages={373--398},
year={1970},
publisher={Blackwell Synergy}
}

@incollection{montague1970befl,
title={English as a formal language},
author={Montague, Richard},
booktitle={Linguaggi nella Societa e nella Tecnica},
editor={Visentini, Bruno and others},
publisher={Edizioni di Comunità},
pages={189--224},
year={1970}
}


Since the sorting order is 1. year, 2. lexicographic by title, you can supply a mock argument to the title: write this in your LaTeX document

\newcommand{\mockalph}[1]{}


and insert the titles respectively as

title={{\mockalph{bbbbb}}Universal grammar},

title={{\mockalph{ccccc}}English as a formal language},


so that the ordering will be with respect to bbbbb and ccccc, which won't be printed anyway.

Why not aaaaa for the first? Well, if you discover a book by Montague that's been printed before "Universal grammar", …