Didier Dubois Henri Prade Thomas Sudkamp A Discussion of Indices for the Evaluation of Fuzzy Associations in Relational Databases. 111-118 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2715&spage=111 2003 conf/ifsa/2003 IFSA db/conf/ifsa/ifsa2003.html#DuboisPS03