Columbia subject headings:
Germany--Politics and government--1918-1933--Sources.
Kommunistische Partei Deutschlands--History--Sources.
Harvard subject headings:
Communism--Germany--History--Sources.
Germany--Politics and government--1918-1933--Sources.
Kommunistische Partei Deutschlands--History--Sources.
Princeton subject headings:
Communism--Germany--History--Sources.
Germany--Politics and government--1918-1933--Sources.
Kommunistische Partei Deutschlands--History--Sources.