David Bettencourt da Cruz Bernhard Rumpe Guido Wimmel Retrofitting Security into a Web-Based Information System. 301-305 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2722&spage=301 2003 conf/icwe/2003 ICWE db/conf/icwe/icwe2003.html#CruzRW03