Hechenberger, R., P. J. Stuckey, D. Harabor, P. Le Bodic, and M. A. Cheema. “Online Computation of Euclidean Shortest Paths in Two Dimensions”. Proceedings of the International Conference on Automated Planning and Scheduling, vol. 30, no. 1, June 2020, pp. 134-42, https://ojs.aaai.org/index.php/ICAPS/article/view/6654.