Gen.Aniline Works Patent: US2109401 , 1935 ; Full Text Show Details I.G.Farbenind. Patent: GB446829 , 1934 ; Full Text Show Details I.G.Farbenind. Patent: DE646707 , 1934 ; Fortschr. Teerfarbenfabr. Verw. Industriezweige, vol. 24, p. 1045