Kirsten Lenz Andreas Oberweis Inter-organizational Business Process Management with XML Nets. 243-263 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2472&spage=243 2003 conf/dfg/2003 Petri Net Technology for Communication-Based Systems db/conf/dfg/petri2003.html#LenzO03