Columbia subject headings:
Drang nach Osten--History--20th century--Sources.
Geopolitics--Europe, Eastern--History--Sources.
Germany--Foreign relations--Soviet Union--Sources.
Germany--Military policy--History--20th century--Sources.
Germany--Territorial expansion--History--20th century--Sources.
Military planning--Germany--History--20th century--Sources.
Soviet Union--Foreign relations--Germany--History--Sources.
World War, 1939-1945--Causes--History--Sources.
World War, 1939-1945--Soviet Union--History--Sources.
Harvard subject headings:
Soviet Union--Foreign relations--1917-1945--Sources.
Soviet Union--History--1939-1945--Sources.
World War, 1939-1945--Soviet Union--Sources.
Princeton subject headings:
Soviet Union--Foreign relations--1917-1945--Sources.
Soviet Union--History--1939-1945--Sources.
World War, 1939-1945--Soviet Union--Sources.