1. See for example Herring, C. (1963) Magnetism, Eds. G. T. Rado, H. Suhl., Academic Press, New York.
2. Anderson, P. W., (1959) Phys. Rev. 115, 2;
3. Anderson, P. W. (1963) Sol. State Phys. 14, 99,
4. Anderson, P. W. (1963) Magnetism, Eds. G. T. Rado, H. Suhl, Academic Press, New York.
5. McConell, H. M. (1963) J. Chem. Phys.
39, 1910.