1. Numerical Data and Functional Relationships in Science and Technology, edited by K.-H. Hellwege and O. Madelung, Landolt-Börnstein, New Series, Group III, Vol. 17, Pt. a (Springer, Berlin, 1982).
2. J. R. Chelikowsky and M. L. Cohen, Phys. Rev. B 14, 556 (1976).
3. J. R. Chelikowsky and M. L. Cohen, Phys. Rev. B 30, 4828 (1984).
4. S. N. Sahu, J. T. Borenstein, V. A. Singh, and J. W. Corbett, Phys. Status Solidi B 122, 661 (1984).
5. M.-Z. Huang and W. Y. Ching, J. Phys. Chem. Solids 46, 977 (1985).