Columbia subject headings:
Harvard subject headings:
Communism--Soviet Union--History
Germany--Foreign relations--Soviet Union.
Soviet Union--Foreign relations--Germany.
World War, 1939-1945--History.
Princeton subject headings:
Communism--Soviet Union--History.
Germany--Foreign relations--Soviet Union.
Germany. Treaties, etc. 1939 August 23
Soviet Union--Foreign relations--Germany.
World War, 1939-1945--History.