1. Grüner, G., and Mintier, M., 1977, Adv. Phys.
26, 231.
2. Harrison, W. A., 1966, Pseudopotentials in the Theory of Metals (Benjamin, New York).
3. Harrison, W. A., 1970, Solid State Theory (McGraw-Hill, New York).
4. Kaufmann, E. N., and Vianden, R. J., 1979, Rev. Mod. Phys.
51, 161.
5. Krrrel, C., 1963, Quantum Theory of Solids (Wiley, New York).