@inproceedings{KV99c,
	author	    =   "O. Kupferman and M.Y. Vardi",
        title       =   "Model checking of safety properties", 
	booktitle   = 	"Computer Aided Verification, Proc. 11th  Int.
                         Conference",
        series      =   "Lecture Notes in Computer Science",
        volume      =   "1633", 
	pages       =   "172--183", 	  
        publisher   =   "Springer-Verlag",
        year        =   "1999"
}