Columbia subject headings:
Harvard subject headings:
Europe--Civilization--Congresses.
Europe--History--Sources--Congresses.
History, Modern--Congresses.
Material culture--Europe--History--Congresses.
Princeton subject headings:
Europe--Civilization--Congresses.
Europe--History--Sources--Congresses.
History, Modern--Congresses.
Material culture--Europe--History--Congresses.