Alexander Löser Felix Naumann Wolf Siberski Wolfgang Nejdl Uwe Thaden Semantic Overlay Clusters within Super-Peer Networks. 33-47 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2944&spage=33 2003 conf/dbisp2p/2003 DBISP2P db/conf/dbisp2p/dbisp2p2003.html#LoserNSNT03