Surynek, P. et al. 2016. An Empirical Comparison of the Hardness of Multi-Agent Path Finding under the Makespan and the Sum of Costs Objectives. Proceedings of the International Symposium on Combinatorial Search. 7, 1 (Jul. 2016), 145–146. DOI:https://doi.org/10.1609/socs.v7i1.18407.