Columbia subject headings:
Digital preservation--Congresses.
Library materials--Conservation and restoration--Congresses.
Harvard subject headings:
Digital preservation--Congresses.
Library materials--Conservation and restoration--Congresses.
Library materials--Digitization--Congresses.
Newspapers--Conservation and restoration--Congresses.
Newspapers--Digitization--Congresses.
Princeton subject headings:
Digital preservation--Congresses.
Library materials--Conservation and restoration--Congresses.