Rao; Seshadri Proceedings - Indian Academy of Sciences, Section A, 1937 , # 6 p. 241 Chem. Zentralbl., 1938 , vol. 109, # I p. 1356 Full Text Show Details Dey; Row Journal of the Chemical Society, 1923 , vol. 123, p. 3381 Full Text Show Details Dhar Journal of the Chemical Society, 1920 , vol. 117, p. 996