Columbia subject headings:
Harvard subject headings:
Collective bargaining--Metal-workers--Germany--History--Sources.
Deutscher Metallarbeiter-Verband--History--Sources.
Metal-workers--Labor unions--Germany--History--Sources.
Princeton subject headings:
Collective bargaining--Metal-workers--Germany--History--Sources.
Deutscher Metallarbeiter-Verband--History--Sources.
Metal-workers--Labor unions--Germany--History--Sources.