&lt;!DOCTYPE para PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
          "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"&gt;
&lt;para&gt;
Consult &lt;citation&gt;AhoSethiUllman96&lt;/citation&gt; for more details on
abstract syntax tree construction.
&lt;/para&gt;