Tapas Kanungo David M. Mount Nathan S. Netanyahu Christine D. Piatko Ruth Silverman Angela Y. Wu The analysis of a simple <i>k</i>-means clustering algorithm. 100-109 2000 Symposium on Computational Geometry http://doi.acm.org/10.1145/336154.336189 db/conf/compgeom/compgeom2000.html#KanungoMNPSW00