Gen.Aniline and Film Corp. Patent: US2212928 , 1939 ; Full Text Show Details I.G. Farbenind. Patent: DE711775 , 1938 ; DRP/DRBP Org.Chem. Full Text Show Details Sunthankar; Venkataraman Proceedings - Indian Academy of Sciences, Section A, 1950 , # 32 p. 240,247, 248