1. J. C. Culberson and J. Schaeffer. Searching with pattern databases. Advances in Artificial Intelligence (Lecture Notes in Artificial Intelligence 1081), pages 402–416, 1996.
2. I. T. Hernádvölgyi and R. C. Holte. PSVN: A vector representation for production systems. Technical Report TR-99-04, School of Information Technology and Engineering, University of Ottawa, 1999.
3. R. C. Holte, M. B. Perez, R. M. Zimmer, and A. J. MacDonald. Hierarchical A*: Searching abstraction hierarchies efficiently. Proceedings of the Thirteenth National Conference on Artificial Intelligence (AAAI-96), pages 530–535, 1996.
4. R. E. Korf. Finding optimal solutions to Rubik’s cube using pattern databases. Proceedings of the Fourteenth National Conference on Artificial Intelligence (AAAI-97), pages 700–705, 1997.
5. R. E. Korf and Michael Reid. Complexity analysis of admissible heuristic search. Proceedings of the Fifteenth National Conference on Artificial Intelligence (AAAI-98), pages 305–310, 1998.