Novikov,S.S.; Shvekhgeimer,G.A. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1960 , # 11 p. 1878 - 1882 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1960 , # 11 p. 2026 - 2031