Columbia subject headings:
Labor movement--Germany--History--20th century.
Labor unions--Political activity--Germany--History--20th century.
Socialism--Germany--History--20th century.
Working class--Political activity--Germany--History--20th century.
Harvard subject headings:
Labor movement--Germany--History--20th century
Labor unions--Germany--Political activity--History--20th century.
Labor unions--Political activity--Germany--History--20th century.
Socialism--Germany--20th century.
Socialism--Germany--History--20th century
Working class--Germany--Political activity--History--20th century.
Working class--Political activity--Germany--History--20th century.
World War, 1914-1918--Social aspects--Germany
Princeton subject headings:
Labor movement--Germany--History--20th century.
Labor unions--Germany--Political activity--History--20th century.
Socialism--Germany--History--20th century.
Working class--Germany--Political activity--History--20th century.