Andrew Rae Daniel Jackson Prasad Ramanan Jay Flanz Didier Leyman Critical Feature Analysis of a Radiotherapy Machine. 221-234 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2788&spage=221 2003 conf/safecomp/2003 SAFECOMP db/conf/safecomp/safecomp2003.html#RaeJRFL03