Oró, J.; Kimball, A.P. «Synthesis of purines under possible primitive earth conditions. I. Adenine from hydrogen cyanide». Archives of Biochemistry and Biophysics, 94, agost 1961, pàg. 217–227. DOI: 10.1016/0003-9861(61)90033-9. PMID: 13731263.
Oró, J.; Kimball, A.P. «Synthesis of purines under possible primitive earth conditions. I. Adenine from hydrogen cyanide». Archives of Biochemistry and Biophysics, 94, agost 1961, pàg. 217–227. DOI: 10.1016/0003-9861(61)90033-9. PMID: 13731263.