1. Algorithm AS 136: A K-Means Clustering Algorithm;hartigan;Journal of the Royal Statistical Society Series C (Applied Statistics),1979
2. The global k-means clustering algorithm, Pattern Recognition;likas,2003
3. Constrained k-means clustering with background knowledge;wagstaff;ICML,2001
4. Review on determining the number of Cluster in K-Means Clustering;kodinariya;International Journal,2013