Tetsuo Asano. Effective Use of Geometric Properties for Clustering. In Jin Akiyama, Mikio Kano, Masatsugu Urabe, editors, Discrete and Computational Geometry, Japanese Conference, JCDCG 98, Tokyo, Japan, December 9-12, 1998, Revised Papers. Volume 1763 of Lecture Notes in Computer Science, pages 30-46, Springer, 1998.