1. V. P. Nefedov, V. A. Samoilov, N. N. Kudyakova, et al., Izvest. Akad. Nauk SSSR, Seriya Biol., No. 2, 179 (1971).
2. A. A. Pozdnyakov, V. F. Sushkov, V. A. Sergeev, et al., in: Problems in Veterinary Virology [in Russian], No. 11, Moscow (1966), p. 325.
3. V. A. Sergeev, Propagation of Animal Viruses in Tissue Culture [in Russian], Moscow (1966).
4. A. Fischer, Biochem. J.,43, 491 (1948).
5. A. S. Gordon and E. D. Zanjani, in: Kidney Hormones, J. W. Fisher (Editor), London (1971), p. 295.