1. Blashfield, R K., Aldenderfer, M. S., &Morey, L. C. (1982). Cluster analysis software. In P R. Krishnaish & L. N. Kanal (Eds.),Handbook of statistics, Vol. 2: Classification, pattern recognition, and reduction of dimensionality. Amsterdam: North-Holland.
2. Gilpin, A. R. (1985). APPLECOR: An Apple II implementation of hierarchical clustering analysis using the CONCOR algorithm.Behavior Research Methods, Instruments, & Computers,17, 140.
3. Gower, J. C. (1967). A comparison of some methods of cluster analysis.Biometrics,23, 623–637.
4. Johnson, S. C. (1967). Hierarchical clustering schemes.Psychometrika,32, 241–254.
5. Sokal, R. R., &Sneath, P H. A (1963)Principles of numerical taxonomy. New York: Freeman.