Fischer; Baer Helvetica Chimica Acta, 1935 , vol. 18, p. 516 Full Text Show Details Fischer Patent: US2116016 , 1936 ; Full Text Show Details Fischer Patent: DE646407 , 1936 ; Fortschr. Teerfarbenfabr. Verw. Industriezweige, vol. 24, p. 74 Full Text Show Details Fischer Patent: FR804223 ;