1. Brant, D.A.: Ann. Rev. Biophys. Bioeng. 1 (1972).
2. Dewar, M.: Molecular Orbitals. Fortschr. Chem. Forsch. 23 (1971).
3. England, W., Salmon, L. S., Ruedenberg, K.: Molecular Orbitals. Fortschr. Chem. Forsch. 23 (1971).
4. Gould, R: F. (ed.): Bioinorganic Chemistry. Washington: Am. Chem. Soc. Publ. 1971.
5. Jaffe, H.H; Orchin, M.: Symmetry in Chemistry. New York: Wiley 1965.