1. A. D. Malievskii, Dokl. Akad. Nauk SSSR,190, 884 (1970).
2. A. Chichibabin and M. Bestuzhev, Compt. Rend.,200, 342 (1935).
3. M. Repas, V. Macho, and E. Mistrik, Chem. Zvesti,20, 501 (1966).
4. V. V. Vints, V. N. Parfenov, G. U. Stepanyants, and A. D. Malievskii, Izv. Akad. Nauk SSSR, Ser. Khim., 1555 (1973).