for $d in Root('/BookDB/Book') 
where match $d using [/book/review contains "discussion good"] 
return $d    

  <book>
    <!--this is another book-->
    <title>
      Data on the Web
    </title>
    <price>
      34.95
    </price>
    <review>
      A very good discussion of semi-structured database
		systems and XML.
    </review>
  </book>