Shavrin, K. N.; Khusid, A. Kh.; Nefedov, O. M. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1988 , vol. 37, # 11 p. 2394 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1988 , # 11 p. 2652 - 2653