Giacomo Piccinelli Cesare Stefanelli David Trastour Trusted Mediation for E-service Provision in Electronic Marketplaces. 39-50 2001 conf/welcom/2001 WELCOM http://link.springer.de/link/service/series/0558/bibs/2232/22320039.htm db/conf/welcom/welcom2001.html#PiccinelliST01