Columbia subject headings:
Harvard subject headings:
Artisans--Germany--Erftkreis--History.
Erftkreis (Germany)--History.
Handicraft--Germany--Erftkreis--History.
Princeton subject headings:
Handicraft--Germany--Erftkreis--History.
Manufactures--Germany--Erftkreis--History.
Manufacturing industries--Germany--Erftkreis--History.