<book xmlns="http://booknamespace.org" isbn="0974514055">
  <title>Programming Ruby - 2nd Edition</title>
  <description>Second edition of the great book out there</description>
  <contributions>
    <contributor role="author"><name>David Thomas</name></contributor>
    <contributor role="supporting author"><name>Andrew Hunt</name></contributor>
    <contributor role="supporting author"><name>Chad Fowler</name></contributor>
  </contributions>
</book>