1. M. Imlau, Phys. Status Solidi 204, 642 (2007)
2. B.I. Sturman, Photorefractive Materials and Their Applications 1, Chap. 5 (Springer, New York, 2006)
3. M.P. Petrov, V.V. Bryksin, Photorefractive Materials and Their Applications 2, Chap. 9 (Springer, New York, 2007)
4. R.F. Kazarinov, R.A. Suris, B.I. Fuks, Sov. Phys. Semicond. 7, 102 (1973)
5. L. Solymar, D. Walsh, Photorefractive Materials and Their Applications 2, Chap. 8 (Oxford University Press, Oxford, 2004)