@article{Kleinbergetal:jacm04, author = {Kleinberg, Jon and Papadimitriou, Christos and Raghavan, Prabhakar}, title = {Segmentation Problems}, journal = {Journal of the {ACM}}, volume = {51}, issue = {2}, year = {2004}, pages = {263--280}, keywords = {clustering, approximation algorithms, data mining, market segmentation}, }