Columbia subject headings:
Harvard subject headings:
Conflict management--History.
Kosovo War, 1998-1999
United Nations--Peacekeeping forces.
World War, 1914-1918--Causes
Princeton subject headings:
Conflict management.
Kosovo War, 1998-1999.
World War, 1914-1918--Causes.
World War, 1914-1918--Diplomatic history.