[1] B. A. Trahtenbrot, Ya. M.Barzdin': Finite automata (Behavior and synthesis). Nauka, Moscow 1970. MR 0265078

[2] E. F. Moore: Gedanken-experiments on sequential machines. In: Automata Studies. Princeton University Press, New Jersey 1956, 129-153. MR 0078059

[3] A. D. Korshunov: A survey of certain directions of the theory of automata. In: Discrete Analysis, vol. 25. Novosibirsk 1974, 19-55.

[4] A. D. Korshunov: On asymptotic estimates of the number of reduced finite automata. In: Discrete Analysis vol. 6. Novosibirsk 1966, 35-50. MR 0197225

[5] Ya. M. Barzdin' A. D. Korshunov: On the diameter of reduced automata. In: Discrete Analysis, vol. 9. Novosibirsk 1967, 3 - 45. MR 0234772

[6] A. D. Korshunov: On the degree of distinguishability of automata. In: Discrete Analysis, vol. 10. Novosibirsk 1967, 39-59.