1. Chada, M. S., Lawless, J. G., Flores, J. J., and Ponnamperums, C.: 1971, in R. Buvet and C. Ponnamperuma (eds.),Chemical Evolution and Origins of Life, North-Holland, Amsterdam, p. 143.
2. Miller, S. L. and Orgel, L. E.: 1974,The Origins of Life on the Earth, Prentice-Hall, Englewood Cliffs, N.J., p. 199.
3. Draganić, I., Draganić, Z., Petković, Lj., and Nikolić, A.: 1973,J. Amer. Chem. Soc. 95, 7193.
4. Draganić, I. G., Draganić, Z. D., and Shushtarian, M. J.: 1976,Radiat. Res. 66, 54.
5. Draganić, Z., Draganić, I., Shimoyama, A., and Ponnamperuma, C.: 1977,Origins of Life, preceding article.