1. Acyclic Programs;Apt,1990
2. Nonmonotonic Reasoning in the Framework of Situation Calculus;Baker;Artificial Intelligence,1991
3. Baral, C. and Gelfond, M., Representing Concurrent Actions in Extended Logic Programming, Proc. of IJCAI-93, to appear.
4. A Goal-Oriented Approach to Computing Well-Founded Semantics;Chen,1992
5. On the Relations between Stable and Well-Founded Semantics of Logic Programs;Dung;Theoret. Comput. Sci.,1992