Edie M. Rasmussen Information Retrieval Challenges for Digital Libraries. 95-103 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3334&spage=95 2004 conf/icadl/2004 ICADL db/conf/icadl/icadl2004.html#Rasmussen04