1. Hwang, F.K., Richards, D.S., and Winter, P. [1992]: The Steiner Tree Problem; Annals of Discrete Mathematics 53. North-Holland, Amsterdam 1992
2. Goemans, M.X., and Williamson, D.P. [1996]: The primal-dual method for approximation algorithms and its application to network design problems. In: Approximation Algorithms for NP-Hard Problems. (D.S. Hochbaum, ed.), PWS, Boston, 1996
3. Grötschel, M., Monma, C.L., and Stoer, M. [1995]: Design of survivable networks. In: Handbooks in Operations Research and Management Science; Volume 7; Network Models (M.O. Ball, T.L. Magnanti, CL. Monma, G.L. Nemhauser, eds.), Elsevier, Amsterdam 1995
4. Stoer, M. [1992]: Design of Survivable Networks. Springer, Berlin 1992
5. Vazirani, V.V. [2000]: Approximation Algorithms. Springer, forthcoming