Jung Kee Park Hyunchul Kang Handling Updates for Cache-Answerability of XML Queries on the Web. 124-135 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3112&spage=124 2004 conf/bncod/2004 BNCOD db/conf/bncod/bncod2004.html#ParkK04