1. Bonet, B., Geffner, H.: Planning as heuristic search. Artif. Intell. 129(1–2), 5–33 (2001). http://linkinghub.elsevier.com/retrieve/pii/S0004370201001084
2. Cormen, T.H., Leiserson, C.E., Rivest, R.L., Stein, C.: Introduction to Algorithms, 3rd edn. The MIT Press, Cambridge (2009)
3. Dechte, R., Pearl, J.: Generalized best-first search strategies and the optimality of A*. J. ACM 32(3), 505–536 (1985). http://portal.acm.org/citation.cfm?id=3830
4. Haslum, P., Bonet, B., Geffner, H.: New admissible heuristics for domain-independent planning. In: Proceedings of the National Conference on Artificial Intelligence, vol. 20, p. 1163. AAAI Press, MIT Press, Menlo Park, CA, Cambridge, MA, London 1999 (2005). http://scholar.google.com/scholar?hl=en&btnG=Search&q=intitle:New+Admissible+Heuristics+for+Domain-Independent+Planning#0
5. Russell, S.J., Norvig, P.: Artificial Intelligence: A Modern Approach, 3rd edn. Pearson Education, Upper Saddle River (2010)