Dragan Pleskonjic Nemanja Macek Borislav Djordjevic Marko Caric "Security of Computer Systems and Networks" Book Preview. 77-92 2007 4 Comput. Sci. Inf. Syst. 1 http://www.comsis.fon.bg.ac.yu/ComSIS/Vol4No1/BookPreview/Book.htm db/journals/comsis/comsis4.html#PleskonjicMDC07