1. Baral, C.: Knowledge representation, reasoning and declarative problem solving. Cambridge University Press, Cambridge (2003)
2. Balduccini, M., Gelfond, M.: Logic programs with consistency-restoring rules. In: Doherty, P., McCarthy, J., Williams, M.-A. (eds.) International Symposium on Logical Formalization of Commonsense Reasoning, AAAI 2003 Spring Symposium Series, pp. 9–18 (2003)
3. Brewka, G.: Logic programming with ordered disjunction. In: Proc. AAAI-02, pp. 100–105. Morgan Kaufmann, San Francisco (2002)
4. Brewka, G.: Answer sets and qualitative optimization. Logic Journal of the IGPL (2006) (to appear)
5. Brewka, G., Eiter, T.: Preferred answer sets for extended logic programs. Artificial Intelligence 109, 297–356 (1999)