Spaeth; Schmid
Chemische Berichte, 1940 , vol. 73, p. 243

Dvorzhak, D.; Arnol'd, Z.; Kryshtal', G. V.; Yanovskaya, L. A.
Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1983 , vol. 32, # 2 p. 314 - 316
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1983 , # 2 p. 351 - 353