1. Anger, C., Gebser, M., Schaub, T.: Approaching the core of unfounded sets. In: Proceedings of NMR 2006, pp. 58–66 (2006)
2. Bessière, C., Katsirelos, G., Narodytska, N., Walsh, T.: Circuit complexity and decompositions of global constraints. In: Proceedings of IJCAI 2009, pp. 412–418 (2009)
3. Chen, X., Ji, J., Lin, F.: Computing loops with at most one external support rule. ACM Trans. Comput. Logic 14(1), 3:1–3:34 (2013)
4. Clark, K.: Negation as failure. In: Logic and Data Bases, pp. 293–322. Plenum Press (1978)
5. Lecture Notes in Computer Science;M. Denecker,2009