- Anil Nerode, V. Wiktor Marek, V. S. Subrahmanian, editors, Logic Programming and Non-monotonic Reasoning, Proceedings of the First International Workshop, Washington, D.C., USA, July 1991. The MIT Press, 1991.
- LPNMR. 1991.
- LPNMR. 1991.
- LPNMR. 1991.
- LPNMR. 1991.
- LPNMR. 1991.