Columbia subject headings:
Historic sites--Congresses.
Historic sites--Conservation and restoration--Europe, Eastern--Congresses.
Historic sites--Conservation and restoration--Europe--Congresses.
Open-air museums--Abstracts.
Open-air museums--Congresses.
Harvard subject headings:
Princeton subject headings:
Historic sites--Congresses.
Historic sites--Europe, Eastern--Conservation and restoration--Congresses.
Historic sites--Europe--Conservation and restoration--Congresses.
Open-air museums--Abstracts.
Open-air museums--Congresses.