Ákos Schmidt Dániel Varró CheckVML: A Tool for Model Checking Visual Modeling Languages. 92-95 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2863&spage=92 2003 conf/uml/2003 UML db/conf/uml/uml2003.html#SchmidtV03