Petrov, V. A.; Belen'kii, G. G.; German, L. S. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1989 , vol. 38, # 2.2 p. 333 - 339 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1989 , # 2 p. 385 - 391