Guide to LaTeX (4th Edition) (Tools and Techniques

9.3. Bibliographies 219
by the last digits of the year of publication. If the same author has more than
one work in a given year, add a running letter to distinguish them, for example
knu86c, knu86d. With such labels, it is appropriate to make the reference keys
the same as the labels. The indentation depth should be 1.5 cm.
Note: The indentation depth is determined by the argument sample label in the
thebibliography environment. This is usually a dummy text with the right
width. This width can be given precisely with \hspace{width}.
Exercise 9.5: Copy the thebibliography environment from the above exercise
to the end of your standard exercise file (but ahead of the \end{document}
command). Refer to the entries in the bibliography by inserting \cite commands
into your text. Make sure that the key in the \cite command is written exactly
as in the \bibitem command in the thebibliography environment.
9.3.2 Bibliography with BIBT E X
Bibliographic databases and the BIBT E X program are fully described in
Chapter 14. Here we just review the essential aspects for the L AT E X source
file.
• All the information for the literature references is placed in one or
more databases. Each entry is given an identifying key (the key in
the \bibitem argument) which is the handle to refer to it.
• In the source text, citations to the references are made with various
commands like \cite, \citet, \citep, taking the key as argument.
• The bibliography style must be specified somewhere in the document
with \bibliographystyle{bib style}; the bib style determines how
the bibliography is to be formatted; the basic style is plain for
numerical citations, or plainnat with the natbib package.
• Give the command \bibliography{database} where the bibliography
is to appear; database is a list of all databases to be searched.
• Process the source file with L AT E X; run BIBT E X and then L AT E X twice.
BIBT E X writes a bibliography following the formatting specifications of
bib style into a thebibliography environment, storing it in a file with
extension.bbl; this file is input by the \bibliography command.
9.3.3 Numerical citations
Standard L AT E X can only handle numerical bibliographies and citations. In
this case, the citation in the text is made with the command
\cite[extra]{key}