Brandão, Martim, and Ioannis Havoutis. “Learning Sequences of Approximations for Hierarchical Motion Planning”. Proceedings of the International Conference on Automated Planning and Scheduling 30, no. 1 (June 1, 2020): 508-516. Accessed June 13, 2021. https://ojs.aaai.org/index.php/ICAPS/article/view/6746.