1. Brewka, G. and Eiter, T. (1998). Preferred answer sets for extended logic programs. In Cohn, A., Schubert, L., and Shapiro, S., editors, Proceedings of the Sixth International Conference on Principles of Knowledge Representation and Reasoning, pages 86–97, Trento, Italy. Morgan Kaufmann Publishers.
2. Buccafurri, F., Leone, N., and Rullo, P. (1997). Strong and weak constraints in disjunctive Datalog. In Dix, J., Furbach, U., and Nerode, A., editors, Proceedings of the Fourth International Conference on Logic Programming and Non-Monotonic Reasoning, pages 2–17, Dagstuhl Castle, Germany. Springer-Verlag.
3. Cadoli, M., Palopoli, L., Schaerf, A., and Vasile, D. (1999). NP-SPEC: An executable specification language for solving all problems in NP. In Gupta, G., editor, Proceedings of the First International Workshop on Practical Aspects of Declarative Languages, pages 16–30, San Antonio, Texas. Springer-Verlag.
4. Crawford, J. and Auton, L. (1996). Experimental results on the crossover point in random 3-SAT. Artificial Intelligence, 81(1):31–57.
5. Eiter, T. and Gottlob, G. (1995). On the computational cost of disjunctive logic programming: Propositional case. Annals of Mathematics and Artificial Intelligence, 15:289–323.