Rice, Michael, and Vassilis Tsotras. “Bidirectional A* Search With Additive Approximation Bounds”. Proceedings of the International Symposium on Combinatorial Search 3, no. 1 (August 20, 2021): 80-87. Accessed May 4, 2026. https://ojs.aaai.org/index.php/SOCS/article/view/18235.