1. D. Koshland, Horizons of Biochemistry [Russian translation], Mir (1964), p. 209.
2. O. N. Efimov, M. L. Khidekel', P. S. Chekrii, V. A. Avilov, O. N. Eremenko, and A. G. Ovcharenko, Zh. Obshch. Khim.,38, 2668 (1968).
3. V. Huckel, Fundamentals of Theoretical Chemistry [Russian translation], Vol. 2, 12 (1955), p. 55.
4. R. B. King and F. G. A. Stone, J. Amer. Chem. Soc.,82, 4557 (1960).
5. R. D. Brown, J. Chem. Soc., 3249 (1950).