Andrzej Jaworski, Józef S. Kwiatkowski, Bogdan Lesyng: „Why isoguanine and isocytosine are not the components of the genetic code", International Journal of Quantum Chemistry, Supplement: Proceedings of the International Symposium on Quantum Biology and Quantum Pharmacology, 1985, 28 (Supplement S12), pp. 209–216 (doi10.1002/qua.560280720).
Christopher Roberts, Rajanikanth Bandaru, Christopher Switzer: „Theoretical and Experimental Study of Isoguanine and Isocytosine: Base Pairing in an Expanded Genetic System", J. Am. Chem. Soc., 1997, 119 (20), pp. 4640–4649 (doi10.1021/ja970123s).