Martin Karusseit Tiziana Margaria Holger Willebrandt Policy expression and checking in XACML, WS-Policies, and the jABC. 20-26 2008 TAV-WEB http://doi.acm.org/10.1145/1390832.1390836 conf/issta/2008t db/conf/issta/tavweb2008.html#KarusseitMW08