1. M. R. Anderberg: Cluster Analysis for Applications (Academic Press, New York 1973)
2. A.K. Agrawala: IEEE Trans. IT-16, 373 (1970)
3. J.M. Ball: “Classification Analysis”; Tech. Note. Stanford Res. Inst., Menlo Park, California (1970)
4. G. G. Battacharya: “A Simple Method of Resolution of a Distribution into Gaussian Components”; Biometrics (1967)
5. Beale: Bull. I.S.E. (London) 43, Bk. 2, 92 (1969)