Columbia subject headings:
Health insurance--Germany--Düsseldorf--History--19th century.
Workers' compensation--Germany--Düsseldorf--History--19th century.
Harvard subject headings:
Health insurance--Germany (West)--Düsseldorf--History--19th century.
Workers' compensation--Germany (West)--Düsseldorf--History--19th century.
Princeton subject headings:
Health insurance--Germany (West)--Düsseldorf--History.
Working class--Germany (West)--Düsseldorf--History.