1. R. A. Smith, et al., op. cit. (Chap. I, ref. 2).
2. A. G. Blokh, op. cit. (Chap. I, ref. 5).
3. A. P. Ivanov, op. cit. (Chap. I, ref. 4).
4. P.A.Apanasevich and V. S. Aizenshtadt, Tables of the Energy and Photon Distributions in the Spectrum of Equilibrium Radiation [in Russian] (Minsk, Inst. Phys. and Inst. Math. Computation, Belorussian Acad. Sci. Press, 1961 ), 251 pp.
5. L. S. Polak, “The development of quantum physics” [in Russian], A Survey of the Rise of Basic Ideas in Physics, ed. by A. T. Grigoryan and L. S. Polak ( Moscow, USSR Acad. Sci. Press, 1959 ), pp. 323–368.