1. E.W. Wiliams, Semicond. & Semi-Metals, vol. 8, chap. 5, Acad.Press, N.Y. 1972.
2. H.J. Gupuislain, L.Dupe Wupolf and P. Cuplauws, J.Electron.Mater.6, 544 (1977).
3. E.W. Wupilliams, Phys. Review,168 3 922, (1968).
4. K.D. GLINCHUK, Phys.Stat.Sol. (a),18-K23, (1973).
5. G.P. Peka, Sov. Phys. Semicond.,7-8-1100, (1974).