@inproceedings{KV01b,
        author    =   "O. Kupferman and M.Y. Vardi",
        title     =   "On clopen specifications",
        booktitle   =   "Proc. 8th International Conference on Logic
                  for Programming, Artificial Intelligence and
                  Reasoning",         
        series      =   "Lecture Notes in Computer Science",
        volume      =   "?", 
        pages       =   "?",
        publisher   =   "Springer-Verlag",
        year        =   "2001",
}