Raevskii, O. A.; Mumzhieva, N. G.; Kron, T. E.; Tsvetkov, E. N.
Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1981 , vol. 30, # 6 p. 1026 - 1030
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1981 , # 6 p. 1292 - 1296