The Katigen colours of the Farbenfabriken vorm. Friedr. Bayer & Co., Elberfeld : and their application in the various branches of the textile industries (1902)
Farbenfabriken vorm. Friedrich Bayer & Co · Elberfeld : Farbenfabriken vorm. Friedr. Bayer & Co. · leaf 104
Farbenfabriken vorm. Friedrich Bayer & Co. · Dyes and dyeing
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
