[[!meta  title="BibTeX"]]

[BibTex][] is system (tools and file format) for managing references
in [[LaTeX]] documents.  Forget about formatting your bibliography (is
it “publisher (year)” or “publisher: year”?), just add entries for the
works you're referencing, and drop in a `\cite{key}`.  I also use my
[[entrez]] script to pull nicely detailed citations off [PubMed][] and
its related databases.  Once you've added the citation to your
database the first citation, you can reuse that data in any future
paper just by reusing your BibTeX database.  It's wonderful.

Basic usage
===========

At some point in your LaTeX document:

    \bibliographystyle{prsty} % Phys. Rev. style

other syles include `abbrv`, `alpha`, `plain`, `unsrt`, ...
In your LaTeX document where you want the bibliography:

    \bibliography{wtk} % wtk.bib is the name of the database

compile (using `latex` for example) with:

    $ latex example
    $ bibtex example
    $ latex example
    $ latex example

Formatting names
================

There are many possible author name formats, but the least ambiguous
is `von Last, Jr., First Middle`.  If the `von` is capitalized
(e.g. "Emanuela Di Cola"), use `\uppercase`:

    @String{EDCola = "{\uppercase{d}}i Cola, Emanuela"}

See [Tame the BeaST][TTB] for details.

Natbib
======

I don't actually use LaTeX's `\cite{key}` command as I claimed above.
That works, but the [Natbib][] package adds support for other citation
styles & link formats.  I actually use `\citep{key}` (parenthetical
citations), `\citet{key}` (textual citations), and other more
specialized Natbib commands.  That way I don't have to worry about
misspelling author names or remembering “et al.” when I cite a source
in the text.

[Natbib]: http://www.ctan.org/tex-archive/help/Catalogue/entries/natbib.html

Makebst
=======

Customize bibliography with Makebst (`latex makebst`, from
[custom-bib][]), makes `.bst` (bib-style) format files according to
your specifications.

Cross-references (more like sub-references)
===========================================

[Don't repeat yourself][DRY]!  BibTeX lets you piggyback low level
references (`@inbook`, `@inproceedings`) underneath higher level
references (`@book`, `@proceedings`) without duplicationg information
from the parent entry (via `crossref`).  However, this can be a bit
tricky.

Like a number of TeX tools, BibTeX tries to accomplish as much as
possible with a single pass through your data.  This makes things more
memory efficient (if you really can't spare that extra MB ;), but it
also makes for some odd errors.  While working on my [[thesis]], I ran
into:

    $ bibtex root
    …
    Database file #9: root.bib
    Warning--string name "nist:esh" is undefined
    --line 1175 of file root.bib
    A bad cross reference---entry "NIST:gumbel"
    …

The problem is due to the `@inbook` entries occuring after the `@book`
they reference:

    @book{ NIST:ESH,
      …
    }

    @inbook{ NIST:gumbel,
      crossref = {NIST:ESH},
      …
    }

When it's reading your bibliography, BibTeX hits the `@book` entry
(`NIST:ESH`), and says to itself, “Hmm, it doesn't look like anyone's
referencing `NIST:ESH`.  I'll save some memory by forgetting I've seen
it.”  Then when BibTeX hits the `@inbook` entry (`NIST:gumbel`), it
says, “Ahh, this references `NIST:ESH`.  I'd better keep an eye out
for that.”  Unfortunately, this is too late, because it's already past
that entry.  BibTeX hits the end of the database without finding a
(second) `NIST:ESH` definition, and complains about the missing
reference.

The solution is just to order your `@inbooks` (and other `crossref`
consumers) so they occur before the entry they reference:

    @inbook{ NIST:gumbel,
      crossref = {NIST:ESH},
      …
    }

    @book{ NIST:ESH,
      …
    }

Embarassingly, this information is spelled out on [Wikipedia's BibTeX
page][wikipedia]:

> The referred entry must stand below the referring one.

That's the kind of thing you'll only remember after you've been bitten
by it ;).  Hopefully putting the `bad cross reference` error message
in the surrounding text will help the rest of you searching for
solutions.

It looks like [Matěj Cepl][MC] (who has also
[contributed][MC-rss2email] to [[rss2email]]) ran into [the same
issue][lyx-2000-11-07] back in 2000.  It's a small world ;).

References
==========

There are a number of good resources to get you going:

* [very basic tutorial](http://cmtw.harvard.edu/Documentation/TeX/Bibtex/Example.html)
* really awesome explanation of how BibTeX works: [Tame the
  BeaST][TTB]
* [process overview](http://www.andy-roberts.net/misc/latex/latextutorial3.html)
* [entry types reference](http://newton.ex.ac.uk/tex/pack/bibtex/btxdoc/node6.html)
* [fields reference](http://newton.ex.ac.uk/tex/pack/bibtex/btxdoc/node7.html)
* [entry and fields reference](http://en.wikipedia.org/wiki/BibTeX),
  but with little discussion
* [examples](http://www.cs.stir.ac.uk/~kjt/software/latex/showbst.html)
  of assorted styles
* [assorted tools](http://liinwww.ira.uka.de/bibliography/Bib.Format.html)
* Nelson Beebe's
  [list of bibliographies](http://www.math.utah.edu/~beebe/bibliographies.html)
* Nelson Beebe's
  [GNU bibliography](http://www.math.utah.edu/pub/tex/bib/gnu.html)

[BibTeX]: http://www.bibtex.org/
[PubMed]: http://www.ncbi.nlm.nih.gov/pubmed/
[TTB]: http://www.ctan.org/tex-archive/info/bibtex/tamethebeast/
[Natbib]: http://merkel.zoneo.net/Latex/natbib.php
[custom-bib]: http://www.ctan.org/tex-archive/help/Catalogue/entries/custom-bib.html
[DRY]: http://en.wikipedia.org/wiki/Don%27t_repeat_yourself
[wikipedia]: https://en.wikipedia.org/wiki/BibTeX#Cross-referencing
[MC]: http://luther.ceplovi.cz/blog/
[MC-rss2email]: http://search.gmane.org/?query=&author=Cepl&group=gmane.mail.rss2email&sort=relevance&DEFAULTOP=and&xFILTERS=Gmail.rss2email-Acepl---A
[lyx-2000-11-07]: http://www.mail-archive.com/lyx-users@lists.lyx.org/msg07511.html

[[!tag tags/latex]]
[[!tag tags/programming]]
[[!tag tags/tools]]