Feng Chen Shaoyun Li Hongji Yang Enforcing Role-Based Access Controls in Software Systems with an Agent Based Service Oriented Approach. 483-488 2007 ICNSC http://dx.doi.org/10.1109/ICNSC.2007.372826 conf/icnsc/2007 db/conf/icnsc/icnsc2007.html#ChenLY07