1. 1. E.L. Ivchenko, G.E. Pikus: Pis’ma ZhETF 27, 640 (1978) [JETP Lett. 27, 604 (1978)]
2. 2. V.I. Belinicher: Phys. Lett. A 66, 213 (1978)
3. 3. V.I. Belinicher, B.I. Sturman: Usp. Fiz. Nauk 130, 415 (1980) [Sov. Phys. Usp. 23, 199 (1980)]
4. 4. B.I. Sturman, V.M. Fridkin: The Photovoltaic and Photorefractive Effects in Non-Centrosymmetric Materials (Gordon and Breach Science Publishers, New York 1992)
5. 5. V.M. Asnin, A.A. Bakun, A.M. Danishevskii, E.L. Ivchenko, G.E. Pikus, A.A. Rogachev: Pis’ma ZhETF 28, 80 (1978); Solid State Commun. 30, 565 (1979)