Columbia subject headings:
Harvard subject headings:
Geopolitics--Europe--History--20th century--Congresses.
Political psychology--Europe--History--20th century--Congresses.
World War, 1914-1918--Europe--Congresses.
World War, 1914-1918--Peace--Congresses.
Princeton subject headings:
Geopolitics--Congresses.
Violence--Europe--History--20th century--Congresses.
World War, 1914-1918--Political aspects--Congresses.