Giacomo Cabri Luca Ferrari Letizia Leonardi Applying security policies through agent roles: A JAAS based approach. 127-146 2006 59 Sci. Comput. Program. 1-2 http://dx.doi.org/10.1016/j.scico.2005.07.008 db/journals/scp/scp59.html#CabriFL06