| [ref.13] | Oró, J.: Synthesis of Adenine From Ammonium Cyanide. Biochem. Biophys. Res. Commun., vol. 2, 1960, p. 407. |
| [ref.14] | ([1], [2]) Ponnamperuma, C.; Sagan, C.; and Mariner, R.: Synthesis of Adenosine Triphosphate Under Possible Primitive Earth Conditions. Nature, vol. 199, 1963, p. 222. |
| [ref.15] | ([1], [2], [3], [4]) Oparin, A. I.: The Origin of Life. Macmillan Co. (New York), 1938. |
| [ref.16] | ([1], [2]) Calvin, M.: Reduction of Carbon Dioxide in Aqueous Solutions by Ionizing Radiation. Science, vol. 114, 1951, p. 416. |
| [ref.17] | Miller, S. L.: A Production of Amino Acids Under Possible Primitive Earth Conditions. Science, vol. 117, 1953, pp. 528-529. |
| [ref.18] | Oró, J.: Studies in Experimental Cosmochemistry. Ann. N. Y. Acad. Sci., vol. 108, 1963, pp. 464-481. |
| [ref.19] | Ponnamperuma, C.: Chemical Evolution and the Origin of Life. Nature, vol. 201, 1964, pp. 337-340. |
| [ref.20] | Bernal, J. D.: The Physical Basis of Life. Routledge & Kegan-Paul (London), 1951. |
| [ref.21] | Fox, S.: Anhydrocopolymerization of Amino Acids Under the Influence of Hypothetically Primitive Terrestrial Conditions. Federation Proc., vol. 13, 1954, p. 211. |
| [ref.22] | Akabori, S.: On the Origin of the Fore-Protein. In The Origin of Life on the Earth. A. I. Oparin et al., eds., Pergamon Press (New York), 1955, p. 189. |