Stav Ashur, Matthew J. Katz. A 4-Approximation of the $\frac{2\pi }{3}$-MST. In Anna Lubiw, Mohammad R. Salavatipour, editors, Algorithms and Data Structures - 17th International Symposium, WADS 2021, Virtual Event, August 9-11, 2021, Proceedings. Volume 12808 of Lecture Notes in Computer Science, pages 129-143, Springer, 2021. [doi]
Abstract is missing.