Saartje Brockmans Raphael Volz Andreas Eberhart Peter Löffler Visual Modeling of OWL DL Ontologies Using UML. 198-213 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3298&spage=198 2004 conf/semweb/2004 International Semantic Web Conference db/conf/semweb/iswc2004.html#BrockmansVEL04