Jerzy W. Jaromczyk, Miroslaw Kowaluk. A geometric proof of the combinatorial bounds the number of optimal solutions for the 2-center euclidean problem. In Proceedings of the 7th Canadian Conference on Computational Geometry, Quebec City, Quebec, Canada, August 1995. pages 19-24, Carleton University, Ottawa, Canada, 1995. [doi]
Abstract is missing.