1. Dewar, M. J. S., and Lepley, A. R. (1961)J. Amer. Chem. Soc. 83, 4560.
2. Gabe, E. J., Le Page, Y., Charland, J-P., Lee, F. L., and White, P. S. (1989)J. Appl. Crystallogr. 22, 384.
3. Gougoutas, Z. J., and Lessinger, L. (1973)J. Solid State Chem. 7, 175.
4. International Tables for X-ray Crystallography (1974). Vol. IV, (Kynoch Press, Birmingham), pp. 99?101, 149?150. (Present Distributor Kluwer Academic Publishers, Dordrecht).
5. Isaacs, S. N. (1972)Experiments in physical organic chemistry (Macmillan, London), p. 108.