Keiko, N. A.; Rulev, A. Yu.; Kalikhman, I. D.; Voronkov, M. G. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1984 , vol. 33, p. 1715 - 1716 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1984 , # 8 p. 1878 - 1879