Lempert, Anna, Alexander Kazakov, and Quang Mung Le. “On Reserve and Double Covering Problems for the Sets With Non-Euclidean Metrics”. Yugoslav Journal of Operations Research 29, no. 1 (February 1, 2019): 69–79. Accessed August 26, 2025. https://yujor.erc.fon.bg.ac.rs/index.php/yujor/article/view/560.