Säurefarbstoffe im Druck auf Wolle = Colorants acides dans l'impression sur laine = Acid colours for wool printing = Coloranti acidi nella stampa della lana (1900)
Sandoz, Inc · [Basel] : Sandoz · leaf 15
Dyes and dyeing
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
