Columbia subject headings:
Europe--History--1918-1945.
Europe--Politics and government--1918-1945.
World War, 1939-1945--Causes.
Harvard subject headings:
Europe--History--1918-1945.
World War, 1939-1945--Causes.
Princeton subject headings:
Europe--History--1918-1945.
World War, 1939-1945--Causes.