Kulikov, A. S.; Makhova, N. N.; Khmel'nitskii, L. I. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1991 , vol. 40, # 2.2 p. 438 - 441 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1991 , vol. 40, # 2 p. 506 - 509