Guobiao Hu Shuigeng Zhou Jihong Guan Xiaohua Hu Towards effective document clustering: A constrained K-means based approach. 1397-1409 2008 44 Inf. Process. Manage. 4 http://dx.doi.org/10.1016/j.ipm.2008.03.001 db/journals/ipm/ipm44.html#HuZGH08