Fabián A. Chudak, Tim Roughgarden, David P. Williamson. Approximate k-MSTs and k-Steiner Trees via the Primal-Dual Method and Lagrangean Relaxation. In Karen Aardal, Bert Gerards, editors, Integer Programming and Combinatorial Optimization, 8th International IPCO Conference, Utrecht, The Netherlands, June 13-15, 2001, Proceedings. Volume 2081 of Lecture Notes in Computer Science, pages 60-70, Springer, 2001. [doi]
Abstract is missing.