1. A. A. Andronov, V. A. Kozlov, L. S. Masov andV. N. Shastin,Pis'ma ZhETF 30 (1979) 585.
2. A. A. Andronov andJ. K. Pozela, ?Inverted Hot Electron Distributions in Semiconductors? (Gorkii, Moscow, 1983, in Russian).
3. S. Komiyama,Adv. Phys. 31 (1982) 259.
4. A. A. Andronov, ?Semiconductors in Infrared and Millimeter Waves?, edited by K. J. Button (Orlando, 1986) vol. 16, p. 149.
5. Yu. B. Vasil'ev andYu. L. Ivanov,Pis'ma v ZhTF 9 (1983) 613;ibid 10 (1984) 949.