Columbia subject headings:
Europe--Politics and government--20th century.
World War, 1914-1918--Causes.
World politics.
Harvard subject headings:
Europe--Politics and government--20th century.
World War, 1914-1918--Causes
World politics.
Princeton subject headings:
Europe--Politics and government--20th century.
World War, 1914-1918--Causes.
World politics.