Guttmann-Beck, Nili, Eyal Knaan, and Michal Stern. “Approximation Algorithms for Not Necessarily Disjoint Clustered TSP”. Journal of Graph Algorithms and Applications 22, no. 4 (September 1, 2018): 555–575. Accessed December 7, 2025. https://jgaa-v5.cs.brown.edu/index.php/jgaa/article/view/paper478.