Stefano Rizzi Elisa Bertino Barbara Catania Matteo Golfarelli Maria Halkidi Manolis Terrovitis Panos Vassiliadis Michalis Vazirgiannis Euripides Vrachnos Towards a Logical Model for Patterns. 77-90 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2813&spage=77 2003 conf/er/2003 ER db/conf/er/er2003.html#RizziBCGHTVVV03