1. L.E. Lamb, Cardiologia48, 118 (1966).
2. V.F. Makeeva, G.S. Komolova, L.V. Serova, E.V. Belikova and I.A. Egorov, Kosmicheskaja bil. med.3, 14 (1976), in Russian.
3. M.S. Gaevskaja, N.A. Veresotskaja, N.S. Kolganova, E.V. Kolchina, L.M. Kurkina and E.A. Nosova, Kosmicheskaja bil. med.5, 37 (1976), in Russian.
4. G.G. Revich, N.P. Rassolova and V.A. Zaharchenko, Kosmicheskaja bil. med.4, 31 (1975), in Russian.
5. G.I. Dorofeev, L.A. Kojemiakin and V.T. Ivashkin, in: Ziklicheskie nukleotidi i adaptazia organisma, p. 122. Ed. A.M. Ugolev, Nauka, Leningrad 1979, in Russian.