1. .A. Aggoun, D. Chan, P. Dufresne, and other. Eclipse user manual release 5.0. ECLiPSe is available at http://www.icparc.ic.ac.uk/eclipse , 2000.
2. P. Cholewiłski, V. Marek, A. Mikitiuk, and M. Truszczyłski. Experimenting with non monotonic reasoning. In Proceedings of the International Conference on Logic Programming, pages 267–281. MIT Press, 1995.
3. T. Eiter, N. Leone, C. Mateis, G. Pfeifer, and F. Scarcello. A deductive system for non monotonic reasoning. In J. Dix, U. Furbach, and A. Nerode, editors, Proceedings of the Fourth International Conference on Logic Programming and Non-Monotonic Reasoning, volume 1265 of Lecture Notes in Artificial Intelligence, pages 363–374. Springer Verlag, 1997.
4. M. Gelfond and V. Lifschitz. The stable model semantics for logic programming. In Proceedings of the International Conference on Logic Programming, 1988.
5. M. Gelfond and V. Lifschitz. Classical negation in logic programs and deductive databases. New Generation Computing, 9:365–385, 1991.