1. R.E. Kofahl and H.J. Lucas, I. Amer. Chem. Soc. 76, 3931 (1954).
2. R. Schoental and E.J.Y. Scott, J. Chem. Soc. 1949, 1683.
3. B. Pullman and A. Pullman, Quantum Biochemistry, John Wiley and Sons, New York, 1963, p. 118.
4. S.S. Epstein, M. Small, H.L. Folk and N. Mantel, Cancer Res., 24, 855 (1964).
5. P.O.P. Ts’o and P. Lu, Proc. Nat. Acad. Sci. 51, 272 (1964).