Columbia subject headings:
Labor laws and legislation--Germany--Prussia--History--19th century.
Working class--Political activity--Germany--Prussia--History--19th century.
Harvard subject headings:
Labor laws and legislation--Germany--Prussia--History--19th century.
Working class--Germany--Prussia--Political activity--History--19th century.
Princeton subject headings:
Labor laws and legislation--Germany--Prussia--History--19th century.
Working class--Germany--Prussia--Political activity--History--19th century.