Hesham Anan Jianfeng Tang Kurt Maly Michael L. Nelson Mohammad Zubair Zhao Yang Challenges in Building Federation Services over Harvested Metadata. 602-614 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2911&spage=602 2003 conf/icadl/2003 ICADL db/conf/icadl/icadl2003.html#AnanTMNZY03