Columbia subject headings:
Harvard subject headings:
Europe--Foreign relations--Congresses.
Peace treaties--History--Congresses.
Peace--History--Congresses.
Peace-building--Europe--History--Congresses.
Princeton subject headings:
Europe--Foreign relations--Congresses.
Peace treaties--History--Congresses.
Peace--History--Congresses.
Peace-building--Europe--History--Congresses.