Elisa Bertino Anna Cinzia Squicciarini Ivan Paloscia Lorenzo Martino Ws-AC: A Fine Grained Access Control System for Web Services. 143-171 2006 9 World Wide Web 2 http://dx.doi.org/10.1007/s11280-005-3045-4 db/journals/www/www9.html#BertinoSPM06