Erdem, E., D. Kisa, U. Oztok, and P. Schüller. “A General Formal Framework for Pathfinding Problems With Multiple Agents”. Proceedings of the AAAI Conference on Artificial Intelligence, vol. 27, no. 1, June 2013, pp. 290-6, doi:10.1609/aaai.v27i1.8592.