1. Kaneko, R., and T. Tsuchiya, Kogyo Kagaku Zasshi 57:526 (1954).
2. Tsuchiya, T., A. Kato and T. Endo, Rep. Govt. Chem. Ind. Res. Inst. Tokyo 51:359 (1956); T. Tsuchiya, and A. Kato, Tokyo Kogyo Shikensho Hokoku 53:230 (1958).
3. Ohta, G., and M. Shimizu, Pharm. Bull. (Tokyo) 5:40 (1957); G. Ohta, and M. Shimizu, Ibid. 6:325 (1958).
4. Kato, A., Yukagaku 10:679 (1961).
5. Tanaka, A., A. Kato and T. Tsuchiya, Ibid. 13:260 (1964).