Columbia subject headings:
Castles--France--History--Congresses.
France--Civilization--1328-1600--Congresses.
Harvard subject headings:
Castles--France--History--Congresses.
France--Civilization--1328-1600--Congresses.
Princeton subject headings:
Architecture and society--France--History--Congresses.
Architecture and society--Great Britain--History--Congresses.
Castles--France--History--Congresses.
Castles--Great Britain--History--Congresses.