Alexander Knapp Nora Koch Gefei Zhang Hanns-Martin Hassler Modeling Business Processes in Web Applications with ArgoUWE. 69-83 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3273&spage=69 2004 conf/uml/2004 UML db/conf/uml/uml2004.html#KnappKZH04