Columbia subject headings:
Harvard subject headings:
Anarchism--Germany--History--20th century.
Freie Arbeiter-Union Deutschlands--History.
Labor movement--Germany--History--20th century
Labor unions--Germany--History--20th century
Press, Labor--Germany--History--20th century.
Syndicalism--Germany--History--20th century.
Princeton subject headings:
Press, Labor--Germany--History--20th century.
Syndicalism--Germany--Periodicals--History--20th century.