Alessandro Agostini Gianluca Moro Identification of Communities of Peers by Trust and Reputation. 85-95 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3192&spage=85 2004 conf/aimsa/2004 AIMSA db/conf/aimsa/aimsa2004.html#AgostiniM04