Giunchiglia, E., Kartha, G. N., & Lifschitz, V. (1997). Representing Action: Indeterminacy and Ramifications. *Artificial Intelligence*, 95, 409–443.

Giunchiglia, E., & Lifschitz, V. (1998). An Action Language Based on Causal Explanation: Preliminary Report. In *Proceedings of the Fifteenth National Conference on Artificial Intelligence*
(AAAI '98), pp. 623–630.

Haslum, P., & Geffner, H. (2000). Admissible Heuristics for Optimal Planning. In Chien, S., Kambhampati, S., & Knoblock, C. A. (Eds.), *Proceedings of the Fifth International Conference on* Artificial Intelligence Planning and Scheduling (AIPS'00), pp. 140–149, Breckenridge, Colorado, USA. AAAI Press.

Kautz, H., & Walser, J. P. (1999). State-space planning by integer optimization. In Proceedings of the 16th National Conference on Artificial Intelligence (AAAI-99), pp. 526–533.

Koehler, J. (1998). Planning Under Resource Constraints. In Proceedings of the 13th European Conference on Artificial Intelligence (ECAI'98), pp. 489–493.

Krentel, M. (1992). Generalizations of Opt P to the Polynomial Hierarchy. *Theoretical Computer* Science, 97(2), 183–198.

Lee, J., & Lifschitz, V. (2001). Additive Fluents. In Provetti, A., & Cao, S. T. (Eds.), *Proceedings* AAAI 2001 Spring Symposium on Answer Set Programming: Towards Efficient and Scalable Knowledge Representation and Reasoning, pp. 116–123, Stanford, CA. AAAI Press.

Lifschitz, V., & Turner, H. (1994). Splitting a Logic Program. In Van Hentenryck, P. (Ed.), *Proceedings of the 11th International Conference on Logic Programming (ICLP'94)*, pp. 23–37, Santa Margherita Ligure, Italy. MIT Press.

Lifschitz, V., & Turner, H. (1999). Representing Transition Systems by Logic Programs. In Gelfond, M., Leone, N., & Pfeifer, G. (Eds.), *Proceedings of the 5th International Conference on Logic* Programming and Nonmonotonic Reasoning (LPNMR'99), No. 1730 in Lecture Notes in AI
(LNAI), pp. 92–106, El Paso, Texas, USA. Springer Verlag.

Lifschitz, V. (1996). Foundations of Logic Programming. In Brewka, G. (Ed.), *Principles of Knowledge Representation*, pp. 69–127. CSLI Publications, Stanford.

Lifschitz, V. (1999a). Action Languages, Answer Sets and Planning. In Apt, K., Marek, V. W.,
Truszczy´nski, M., & Warren, D. S. (Eds.), *The Logic Programming Paradigm - A 25-Year* Perspective, pp. 357–373. Springer Verlag.

Lifschitz, V. (1999b). Answer Set Planning. In Schreye, D. D. (Ed.), Proceedings of the 16th International Conference on Logic Programming (ICLP'99), pp. 23–37, Las Cruces, New Mexico, USA. The MIT Press.

McCain, N. (1999). The Causal Calculator Homepage.. http://www.cs.utexas.edu/
users/tag/cc/.

McCain, N., & Turner, H. (1997). Causal Theories of Actions and Change. In Proceedings of the 15th National Conference on Artificial Intelligence (AAAI-97), pp. 460–465.

McCain, N., & Turner, H. (1998). Satisfiability Planning with Causal Theories. In Cohn, A. G.,
Schubert, L., & Shapiro, S. C. (Eds.), *Proceedings Sixth International Conference on Principles of Knowledge Representation and Reasoning (KR'98)*, pp. 212–223. Morgan Kaufmann Publishers.