1. For example, see Streitweiser, Jr., A.: Molecular orbital theory for organic chemist, Chap. 11. New York: Wiley, N.Y. 1961; or Murrell, J. N., Harget, A. J.: Semi-empirical self-consistent-field molecular orbital theory of molecules, Chap. 1. New York: Wiley, N.Y., 1972
2. Kang, S., Beveridge, D. L.: Theoret. Chim. Acta (Berl.) 22, 312 (1971)
3. Kang, S., Cho, M.-H.: Int. J. Quant. Chem., Symp. No. 7, 319 (1973)
4. Streitweiser, Jr., A., Mowery, P. C., Jesaitis, R. G., Lewis, A.: J. Am. Chem. Soc. 92 6529 (1970)
5. Brownlee, R. T. C., Taft, R. W.: J. Am. Chem. Soc. 90, 6537 (1968)