Gen. Aniline Works Patent: US2086704 , 1934 ; Full Text Show Details I.G. Farbenind. Patent: DE614196 , 1933 ; Fortschr. Teerfarbenfabr. Verw. Industriezweige, vol. 22, p. 1126,1130 Full Text Show Details Krepelka; Stefec Collection of Czechoslovak Chemical Communications, 1937 , vol. 9, p. 29,31