Columbia subject headings:
Elberfeld (Wuppertal, Germany)--Social conditions.
Social structure--Germany--Elberfeld (Wuppertal)--History.
Harvard subject headings:
Elberfeld (Wuppertal, Germany)--Social conditions.
Social structure--Germany--Elberfeld (Wuppertal)--History.
Princeton subject headings:
Elberfeld (Wuppertal, Germany)--History.