Columbia subject headings:
Prussia (Germany)--Politics and government--1870-1947.
Working class--Political activity--Germany--Prussia--History--19th century.
Harvard subject headings:
Prussia (Germany)--Politics and government--1870-1947.
Working class--Germany--Prussia--Political activity--History--19th century.
Princeton subject headings:
Labor movement--Prussia (Germany)--Political activity--History--19th century.
Prussia (Germany)--Politics and government--1870-1947.