参考文献

Gen. Aniline Works Patent: US1874547 , 1928 ; Full Text Show Details Gen. Aniline Works Patent: US1948926 , 1927 ; Full Text Show Details I.G. Farbenind. Patent: DE518316 , 1927 ; Fortschr. Teerfarbenfabr. Verw. Industriezweige, vol. 18, p. 1326 Full Text Show Details I.G. Farbenind. Patent: DE542800 , 1927 ;