<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE book
  PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.7//EN"
  "../dtd/3.1.7/docbookx.dtd">
<book id="book">
<title>Book Title</title>
<chapter id="ch1">
<title>test</title>
<para>How many &deg; can you &copy;.</para>
<para>And what about <xref linkend="ch1"/>.</para>
<para>And what about <xref linkend="s1"/>.</para>
<programlisting>
This is a program
listing.
</programlisting>
</chapter>
</book>