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