...Mermin, Solid State Physics Saunders College, West Washington Square, Philadelphia, PA 19105 (1976) 8. C. Kittel, Quantum Theory of Solids (John Wiley & Sons, Inc., New York, 1963) pp. 368-370 9. G. Baym, Phys. Rev. 135 (1964) A 1691 Chapter Eleven 1. JM Ziman, Principles of...