Indrakshi Ray Tai Xin Concurrent and Real-Time Update of Access Control Policies. 330-339 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2736&spage=330 2003 conf/dexa/2003 DEXA db/conf/dexa/dexa2003.html#RayX03