1. Costantini, S., Lanzarone, G.A., Magliocco, G.: Layer supported models of logic programs. In: Maher, M. (ed.) Proceedings of the 1996 Joint International Conference and Symposium on Logic Programming (JICSLP 1996), pp. 438–452. MIT Press. Cambridge, USA (1996)
2. Dix, J.: A classification theory of semantics of normal logic programs: I. strong properties. Fundam. Inform. 22(3), 227–255 (1995)
3. Dix, J.: A classification theory of semantics of normal logic programs: II. weak properties. Fundam. Inform. 22(3), 257–288 (1995)
4. Van Gelder, A., Ross, K.A., Schlipf, J.S.: The well-founded semantics for general logic programs. J. ACM 38(3), 620–650 (1991)
5. Gelfond, M., Lifschitz, V.: The stable model semantics for logic programming. In: ICLP/SLP, pp. 1070–1080. MIT Press (1988)