R. Wessäly. Network Design: Connectivity and Facilities Location, volume 40 of DIMACS Series in Discrete Mathematics and Theoretical Computer Science, page 425-428. DIMACS/AMS, (1997)
A. Bley, M. Grötschel, and R. Wessäly. Robust Communication Networks: Interconnection and Survivability, volume 53 of DIMACS Series in Discrete Mathematics and Theoretical Computer Science, page 1-16. DIMACS/AMS, (1998)