Karavanov, A. N.; Gryaznov, V. M. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1989 , vol. 38, # 8.1 p. 1593 - 1596 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1989 , # 8 p. 1740 - 1745