[1] M. Loéve: Probability Theory. 3-rd edition, Princeton, N. J.

[2] A. Perez: Notions généralisées d'incertitude, d'entropie et d'information du point de vue de la theorie de martingales. Trans. of First Prague Conf. on Inf. Theory, Stat. Dec. Functions, Random Processes, 1957. Zbl 0102.13204

[3] A. Perez: Information theory methods in reducing complex decision problems. Trans. of Fourth Prague Conf. on Inf. Theory, Stat. Dec. Functions, Random Processes, 1965.

[4] A. Rényi: On the amount of information in a sample concerning a parameter. Publications of the Math. Inst. of the Hungarian Acad. Sci. (in print).