Claudia Picardi Paulo Salles Franz Wotawa An introduction to model-based systems. 1-6 2007 20 AI Commun. 1 http://iospress.metapress.com/openurl.asp?genre=article&issn=0921-7126&volume=20&issue=1&spage=1 db/journals/aicom/aicom20.html#PicardiSW07