Jesús Arias-Fisteus Luis Sánchez Fernández Carlos Delgado Kloos Formal Verification of BPEL4WS Business Collaborations. 76-85 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3182&spage=76 2004 conf/ecweb/2004 EC-Web db/conf/ecweb/ecweb2004.html#Arias-FisteusFK04