Giancarlo Guizzardi Gerd Wagner Nicola Guarino Marten van Sinderen An Ontologically Well-Founded Profile for UML Conceptual Models. 112-126 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3084&spage=112 2004 conf/caise/2004 CAiSE db/conf/caise/caise2004.html#GuizzardiWGMR04