1. S. M. Sze, “Physics of Semiconductor Devices”, 2nd ed., Wiley & Sons, New York 1981.
2. For recent reviews, see: S. Hiyamizu, Proc. 2nd Int. Conf. on “Modulated Semiconductor Structures”, Kyoto, Japan 1985, Surface Sci. (1986, in print)
3. T. P. Pearsall, Surface Sci. 142, 529 (1984).
4. N. J. Shah, S. S. Pei, C. W. Tu, IEEE Trans. Electron. Devices (May 1986, in print).
5. H. Dambkes, K. Heime, Springer Series in Solid State Sciences 53, 125 (1984).