1. Ben’kova, N.P. and Potapova, N.I., Variability of ionospheric parameters, in Dokl. VII nauch. konf. (Proc. the VII Int. Conf.), vol. 2, Tomsk: Tomsk univ., 1957, p. 82.
2. Bunimovich, V.I., Fluktuatsionnye protsessy v radiopriemnykh ustroistvakh (Fluctuation Processes in Radio Variable Instruments), Moscow: Sovetskoe radio, 1951.
3. Chernyshov, O.V., On foEs distribution curves, Geomagn. Aeron., 1968, vol. 8, no. 6, pp. 1114–1115.
4. Cramér, H., Mathematical Methods of Statistics, Uppsala: Almqvist and Wiksells, 1945; Moscow: Mir, 1975.
5. Davenport W.B. and Root, W.L., An Introduction to the Theory of Random Signals and Noise, New York: McGraw-Hill, 1958; Moscow: Inostrannaya Literatura, 1960.