1. V. N. Abakumov andI. N. Yassievich:Sov. Phys. JETP,44, 345 (1976).
2. V. N. Abakumov, L. N. Kreshchuk andI. N. Yassievich:Sov. Phys. Semicond.,12, 264 (1978a); translated fromFiz. Tekh. Poluprovodn.,12, 264 (1978a).
3. V. N. Abakumov, V. I. Perel andI. N. Yassievich:Sov. Phys. Semicona.,12, 1 (1978b).
4. H. Baranger andJ. W. Wilkins:Phys. Rev. B,30, 7349 (1984).
5. V. Bareikis, R. Katilius, A. Matulionis, R. Šaltis, S. Gantsevich, V. Gurevich, Sh. Kogan andA. Shul'man:Lithuan. J. Phys.,31, 3 (1991).