1. Albrecht, G., and Corey, R. B., J. Amer. Chem. Soc., 61, 1087 (1939).
2. Marsh, R. E., Fourth Int. Cong. Crystallography, Paper No. 8-1; Acta Cryst., 10, 814 (1957).
3. Fischer, E., Ber. deut. chem. Ges., 38, 2917 (1905).
4. Bernal, J. D., Z. Krist., 78, 363 (1931).
5. Iitaka, Y., Proc. Japan Acad., 30, 109 (1954).