1<?xml version="1.0" ?>
2<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.0//EN"
3               "/dtd/4.0/docbookx.dtd" [
4  <!ENTITY subdoc SYSTEM "subdoc.ent">
5]>
6
7<book lang="en">
8<title>Main document</title>
9
10<chapter id="main">
11<para>This references to: <link linkend="subdoc"/></para>
12</chapter>
13&subdoc;
14
15</book>
16