Having several keys refer to the same bibliography entry

Question

Is it possible to have several keys referring to the same bibliography entry (using biblatex+Biber)?

For example, I'd like \cite{Tolkien:1954:LordOfTheRings} and \cite{lotr} to have exactly the same effect when used in a document (and produce only a single bibliography entry, when both are used in the same document).

Answer 1

I have something working for this now in the biber 0.9.8 beta which you can get from SourceForge:

https://sourceforge.net/projects/biblatex-biber/files/biblatex-biber/development/

You will also need to be using a slightly hacked biblatex 1.7 .sty from:

https://sourceforge.net/projects/biblatex-biber/files/biblatex-biber/testfiles/biblatex.sty

Then, define your entries as normal but you can use the new "IDS" field for extra citations keys:

@BOOK{key,
  IDS = {key2, key3, ... keyn},
  .
  .
}

You can then cite by any of the keys, you can cite by any of them mixed in the same section and and you can use \nocite{*} too - it won't duplicate entries in the bibliography. In fact, the other keys are just aliases to the main key which owns the entry in the .bbl and are redirected to the main key before any label generation etc. happens.

This interface isn't finalised - I haven't spoken to the biblatex maintainer about incorporating this yet but since it re-directs the citations at a fairly low level, I think it's probably safe. Haven't done too much testing though so please log a bug on the biber SourceForge tracker if you find a problem. Please don't log a bug on the biblatex tracker as it's not official yet.

It will also detect if you use a key as a primary key and also an alias elsewhere, in which case it will disable the alias. It also notices duplicate aliases as well as keys now.

Answer 2

The following, taken from "Alias for BiBTeX Keys" on comp.text.tex, provides \bibalias{<alias>}{<source>} and should use \acite{<citation>} instead of \cite{<citation>}:

\documentclass{article}
\usepackage{biblatex}% http://ctan.org/pkg/biblatex
\bibliography{references}

\makeatletter
% \bibalias{<alias>}{<source>} makes \cite{<alias>} equivalent to \cite{<source>}
\newcommand\bibalias[2]{%
  \@namedef{bibali@#1}{#2}%
}

\newtoks\biba@toks
\newcommand\acite[2][]{%
  \biba@toks{\cite#1}%
  \def\biba@comma{}%
  \def\biba@all{}%
  \@for\biba@one:=#2\do{%
    \@ifundefined{bibali@\biba@one}{%
      \edef\biba@all{\biba@all\biba@comma\biba@one}%
    }{%
      \PackageInfo{bibalias}{%
        Replacing citation `\biba@one' with `\@nameuse{bibali@\biba@one}'
      }%
      \edef\biba@all{\biba@all\biba@comma\@nameuse{bibali@\biba@one}}%
    }%
    \def\biba@comma{,}%
  }%
  \edef\biba@tmp{\the\biba@toks{\biba@all}}%
  \biba@tmp
}
\makeatother

\bibalias{Tolkien:1954:LordOfTheRings}{lotr}

\begin{document}
The reference~\acite{Tolkien:1954:LordOfTheRings} is
exactly the same as~\acite{lotr}.

\bibstyle{plain}
\printbibliography
\end{document}

where references.bib resembles:

@book{lotr,
  author  = "J.R.R. Tolkien",
  title   = "{The Lord of the Rings}",
  address = "New York",
  year    = 1954,
  publisher = "Ballantine Books"
}