Reind P. van de Riet Andrea Junk Ehud Gudes Security in Cyberspace: A Knowledge-Base Approach. 69-96 1997 24 Data Knowl. Eng. 1 db/journals/dke/dke24.html#RietJG97 http://dx.doi.org/10.1016/S0169-023X(97)00002-5