Hartmut Ehrig Behaviour and Instantiation of High-Level Petri Net Processes. 211-247 2005 65 Fundam. Inform. 3 http://iospress.metapress.com/openurl.asp?genre=article&issn=0169-2968&volume=65&issue=3&spage=211 db/journals/fuin/fuin65.html#Ehrig05