Trzhtsinskaya, B. V.; Abramova, N. D.; Rudakova, E. V.; Afonin, A. V.; Keiko, V. V. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1988 , vol. 37, p. 1683 - 1686 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1988 , # 8 p. 1882 - 1885