Columbia subject headings:
Harvard subject headings:
Europe--History--476-1492--Congresses.
Europe--Rural conditions--Congresses
Europe--Social conditions--To 1492--Congresses.
France--History--To 987--Congresses.
France--Rural conditions--Congresses.
France--Social conditions--To 987--Congresses.
Princeton subject headings:
Europe--History--476-1492--Congresses.
Europe--Rural conditions--Congresses.
Europe--Social conditions--To 1492--Congresses.
France--History--To 987--Congresses.
France--Rural conditions--Congresses.
France--Social conditions--To 987--Congresses.