[1] L. E. Baum T. Petrie G. Soules, N. Weiss: 
A maximization technique occurring in the statistical analysis of probabilistic functions of Markov chains. Ann. Math. Statist. 41 (1970), 164-171. 
MR 0287613[2] A. P. Dempster N. M. Laird, and D. B. Rubin: 
Maximum likelihood from incomplete data via the EM algorithm. J. Roy. Statist. Soc. B 39 (1977), 1 - 38. 
MR 0501537[3] J. Grim: 
An algorithm for maximizing a finite sum of positive functions and its application to cluster analysis. Problems Control Inform. Theory 10 (1981), 427-437. 
MR 0643728 | 
Zbl 0476.65100[4] J. Grim: 
On numerical evaluation of maximum-likelihood estimates for finite mixtures of distributions. Kybernetika 18 (1982), 173-190. 
MR 0680154 | 
Zbl 0489.62028[5] J. Grim: Application of finite mixtures to multivariate statistical pattern recognition. In: Proceedings of DIANA Conf. held in Liblice near Prague, September 27-October 1, 1982.
[6] J. Grim: 
Design and optimization of multilevel homogeneous structures for multivariate pattern recognition. In: Proc. Fourth Formator Symposium (J. Beneš, L. Bakule, eds.), Academia, Prague 1983, pp. 223-240. 
MR 0726960 | 
Zbl 0533.62071[7] J. Grim: 
On  structural  approximating  multivariate   discrete  probability   distributions. Kybernetika 20 (1984), 1-17. 
MR 0741419 | 
Zbl 0547.62034[8] S. Kullback: 
Information Theory and Statistics. Dover, New York 1968. 
MR 1461541[9] M. A. G. Mattoso Maia, M. C. Fairhurst: 
On the use of I-divergence for generating distribution approximations. IEEE Trans. Pattern Anal, and Mach. Intel. PAMI-5 (1983), 661-664. 
Zbl 0527.62027[10] R. A. Redner, H. F. Walker: 
Mixture densities, maximum likelihood and the EM algorithm. SIAM Review 26 (1984), 195-239. 
MR 0738930 | 
Zbl 0536.62021[11] M. I. Shlezinger: Relation between learning and self-learning in pattern recognition. (in Russian). Kibernetika (Kiev) (1968), 2, 81-88.
[12] C. F. J. Wu: 
On the convergence properties of the EM algorithm. Ann. Statist. 11 (1983), 95-103. 
MR 0684867 | 
Zbl 0517.62035