1. Algorithm AS 136, A K-means clustering algorithm;Hartigan;J. R. Stat. Soc. Ser. C (Appl. Stat.),1979
2. Efficient and effective clustering methods for spatial data mining;Ng,1994
3. Birch an efficient data clustering method for very large databases;Zhang,1996
4. A density-based algorithm for discovering clusters in large spatial databases with noise;Ester,1996
5. Density-connected sets and their application for trend detection in spatial databases;Ester,1997