Delyagina, N. I.; Igumnov, S. M.; Snegirev, V. F.; Knunyants, I. L.
Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1981 , vol. 30, # 10 p. 1836 - 1840
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1981 , # 10 p. 2238 - 2243