Chen, Xianrun, Dachuan Xu, Yicheng Xu, and Yong Zhang. “Parameterized Approximation Algorithms for Sum of Radii Clustering and Variants”. Proceedings of the AAAI Conference on Artificial Intelligence 38, no. 18 (March 24, 2024): 20666–20673. Accessed May 19, 2026. https://ojs.aaai.org/index.php/AAAI/article/view/30053.