Columbia subject headings:
Art--Conservation and restoration--Congresses.
Paper--Deterioration--Congresses.
Paper--Preservation--Congresses.
Parchment--Conservation and restoration--Congresses.
Harvard subject headings:
Art--Conservation and restoration--Congresses.
Drawing--Conservation and restoration--Congresses.
Paper--Deterioration--Congresses.
Paper--Preservation--Congresses
Parchment--Conservation and restoration--Congresses.
Prints--Conservation and restoration--Congresses.
Princeton subject headings:
Art--Conservation and restoration--Congresses.
Paper--Deterioration--Congresses.
Paper--Preservation--Congresses.
Parchment--Conservation and restoration--Congresses.