Columbia subject headings:
Architecture, Medieval--Europe--Congresses.
Cities and towns, Medieval--Europe--Congresses.
Historic sites--Conservation and restoration--Europe--Congresses.
Harvard subject headings:
Architecture, Medieval--Europe--Congresses.
Cities and towns, Medieval--Europe--Congresses.
Historic sites--Conservation and restoration--Europe--Congresses.
Princeton subject headings:
Architecture, Medieval--France--Congresses.
Cities and towns, Medieval--Congresses.
Fortification--France--Congresses.