[1] Kubota H., Ohzu H.: J. Opt. Soc. Am., 47, 666-667, 1957.

[2] Goldman S.: Information Theory. (New York Prentice-Hall, Inc., 1953), 247. MR 0064349 | Zbl 1151.94459

[3] Ohzu H., Kubota H.: Oyo Buturi, 26, 3, 96-101, 19571

[4] Kretzmer E. R.: The Bell System. Tech. Journal, 751-763, 1952.

[5] Ooue, Sh., Hatanaka I.: Scientific Publications of The Fuji Photo Film Co., LTD, No. 9, 24, 24-30, 1961.