Columbia subject headings:
Harvard subject headings:
Germany--Foreign relations--Soviet Union.
Soviet Union--Foreign relations--1917-1945.
Soviet Union--Foreign relations--Germany.
World War, 1939-1945--Causes.
World War, 1939-1945--Diplomatic history.
Princeton subject headings:
Germany. Treaties, etc. 1939 August 23
Soviet Union--Foreign relations--1917-1945.
World War, 1939-1945--Diplomatic history.