Reidar Conradi Maria Letizia Jaccheri Process Modelling Languages. 27-52 1999 conf/ewspt/1999 Software Process: Principles, Methodology, Technology http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=1500&spage=0027 db/conf/ewspt/sp1999.html#ConradiJ99