Columbia subject headings:
Communism--Germany--Rhineland--History--20th century--Sources.
Demonstrations--Germany--Rhineland--History--20th century--Sources.
Rhineland (Germany)--History--Sources.
Roter Frontkämpferbund--History--Sources.
Working class--Germany--Rhineland--History--20th century--Sources.
Harvard subject headings:
Communism--Germany--Rhineland--History--20th century--Sources.
Demonstrations--Germany--Rhineland--History--20th century--Sources.
Rhineland (Germany)--History--Sources.
Roter Frontkämpferbund--History--Sources.
Working class--Germany--Rhineland--History--20th century--Sources.
Princeton subject headings:
Germany--History--1918-1933.
Germany--Politics and government--1918-1933.
Roter Frontkämpferbund.
Socialism--Germany--Sources.