Vinogradov, M. G.; Tuzikov, A. B.; Nikishin, G. I. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1989 , vol. 38, # 11.2 p. 2353 - 2356 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1989 , # 11 p. 2565 - 2568