1. G.J. Iafrate, H.L. Grubin and D.K. Ferry, J. de Physique C7, 307 (1981).
2. G.J. Iafrate, R. Malik, K. Hess and J. Tang. To be published.
3. See, e.g., A. Sommerfeld, Thermodynamics and Statistical Mechanics, Sec. 43. Adacemic Press, NY (1956).
4. H.L. Grubin and J.P. Kreskovsky, Surface Science 39 (1983).
5. H.L. Grubin, G.J. Iafrate and D.K. Ferry, J. de Physique C7, 201 (1981).