Hanna Bauerdick Martin Gogolla Fabian Gutsche Detecting OCL Traps in the UML 2.0 Superstructure: An Experience Report. 188-196 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3273&spage=188 2004 conf/uml/2004 UML db/conf/uml/uml2004.html#BauerdickGG04