Columbia subject headings:
Harvard subject headings:
Architecture--Conservation and restoration--Estonia--Congresses.
Architecture--Conservation and restoration--Scandinavia--Congresses.
Architecture--Estonia--Conservation and restoration--Congresses.
Architecture--Scandinavia--Conservation and restoration--Congresses.
Historic buildings--Conservation and restoration--Estonia--Congresses.
Historic buildings--Conservation and restoration--Scandinavia--Congresses.
Historic buildings--Estonia--Conservation and restoration--Congresses.
Historic buildings--Scandinavia--Conservation and restoration--Congresses.
Princeton subject headings:
Architecture--Estonia--Conservation and restoration--Congresses.
Architecture--Scandinavia--Conservation and restoration--Congresses.
Historic buildings--Estonia--Conservation and restoration--Congresses.
Historic buildings--Scandinavia--Conservation and restoration--Congresses.