Columbia subject headings:
Germany--History--Revolution, 1918--Sources.
Revolutionaries--Germany--Bremen--Biography.
Revolutions--Germany--Bremen--History--20th century.
Harvard subject headings:
Germany--History--Revolution, 1918--Sources.
Germany--History--Revolution, 1918.
Revolutionaries--Germany--Bremen--Biography.
Revolutions--Germany--Bremen--History--20th century.
Princeton subject headings: