<?xml version="1.0"?>
<element name="Book" ns="http://www.publishing.org"
         xmlns="http://relaxng.org/ns/structure/1.0">
  <element name="Title"><text/></element>
  <oneOrMore>
    <element name="Author"><text/></element>
  </oneOrMore>
  <element name="Date"><text/></element>
  <element name="ISBN"><text/></element>
  <element name="Publisher"><text/></element>
</element>
