Niemelä, I.; Simons, P.; Soinenen, T. (2000). Stable model semantics of weight constraint rules. У Gelfond, Michael; Leone, Nicole; Pfeifer, Gerald (ред.). Logic Programming and Nonmonotonic Reasoning: 5th International Conference, LPNMR '99, El Paso, Texas, USA, December 2–4, 1999 Proceedings. Lecture notes in computer science: Lecture notes in artificial intelligence. Т. 1730. Springer. с. 317—331. ISBN978-3-540-66749-0. as Postscript
Niemelä, I.; Simons, P.; Soinenen, T. (2000). Stable model semantics of weight constraint rules. У Gelfond, Michael; Leone, Nicole; Pfeifer, Gerald (ред.). Logic Programming and Nonmonotonic Reasoning: 5th International Conference, LPNMR '99, El Paso, Texas, USA, December 2–4, 1999 Proceedings. Lecture notes in computer science: Lecture notes in artificial intelligence. Т. 1730. Springer. с. 317—331. ISBN978-3-540-66749-0. as Postscript