1. 1. P.M. Tomchuk, A.A. Chumak, Nonlinear propagation of infrared radiation in many-valley semiconductors // Fiz. Tekh. Poluprov. 19(1), p. 77-82 (1985).
2. 2. V.N. Poroshin, O.G. Sarbey, V.M. Vasetskii, Nonlinear optical phenomena resulting from carrier heating in many-valley semiconductors // Ukr. J. Phys. 44(1-2), p. 60-65 (1999).
3. 3. M. Vasetskii, V.N. Poroshin, V.A. Ignatenko, Degenerate four-wave mixing in n-Ge due to intervalley redistribution of hot electrons // Semiconductor Physics, Quantum Electronics & Optoelectronics 4(4), pp. 260-263 (2001).
4. 4. H.Y. Fan, Photon-electron interaction, crystals without fields, Springer-Verlag, Berlin, Heidelberg, New York (1967).
5. 5. H.J.G. Meyer, Infrared absorption by conduction electrons in germanium // Phys. Rev. 112(2), p. 298- 308 (1958).