1. For a recent review see Bassani, F., Iadonisi, G., and Preziosi, B., Reports on Progr. in Phys. 37, 1099 (1974). Also Ref. [2].
2. Pantelides, S. T., Rev. Mod. Phys., to be published.
3. See e. g. Kukimoto, H., Henry, C. H., and Merritt, F. R., Phys. Rev. B 7, 2486 (1973); Jayson, J. S., Bachrach, R. Z., Dapkus, P. D., and Schumaker, N. E., Phys. Rev. B 6, 2357 (1972).
4. Kohn, W., Solid State Phys. 5, 257 (1957).
5. Bethe, H. A., “Theory of the Boundary Layer of Crystal Rectifiers” MIT Rad. Lab. Rep. 43-12, Nov. 23, 1942. At. that time donors were referred to as “donators”; see reference [2] for historical review.