Columbia subject headings:
World War, 1914-1918--Causes.
World War, 1914-1918--Diplomatic history.
Harvard subject headings:
World War, 1914-1918--Causes
World War, 1914-1918--Diplomatic history
Princeton subject headings:
World War, 1914-1918--Causes.
World War, 1914-1918--Diplomatic history.