1. Brown, E. H., Wilhide, W. D., and Elmore, K. L., 1962, J. Org. Chem., 27: 3698.
2. Denaro, A. R., and Hickling, A., 1958, J. Electrochem. Soc., 105: 265.
3. Ebisawa, H., Mitsugi, E., Shirai, T., and Yanagisawa, S., 1979, Nippon Kagaku Zasshi, 1304.
4. Fox, S. W., and Dose, K., 1977, “Molecular Evolution and the Origin of Life,” 2nd edn., Marcel Dekker, New York (literatures listed therein).
5. Harada, K., 1974, in: “The Origin of Life and Evolutionary Biochemistry,” K. Dose, S. W. Fox, G. A. Deborin, and T. E. Pavlovskaya, eds., p. 183, Plenum, New York.