Columbia subject headings:
Harvard subject headings:
Communism--Germany--Hamburg--History--20th century.
Communism--Germany--History--20th century
Germany--Politics and government--1918-1933
Hamburg (Germany)--Politics and government--20th century.
Princeton subject headings:
Communism--Germany--Hamburg--History--20th century.
Communism--Germany--History--20th century.
Germany--Politics and government--1918-1933.
Hamburg (Germany)--Politics and government--20th century.