Yap, P., N. Burch, R. Holte, and J. Schaeffer. “Block A*: Database-Driven Search With Applications in Any-Angle Path-Planning”. Proceedings of the AAAI Conference on Artificial Intelligence, vol. 25, no. 1, Aug. 2011, pp. 120-5, doi:10.1609/aaai.v25i1.7813.