Columbia subject headings:
Documents in optical storage.
Electronic records.
Image processing--Digital techniques.
Library materials--Conservation and restoration.
Harvard subject headings:
Digital preservation--United States.
Documents in optical storage.
Electronic records.
Image processing--Digital techniques.
Library materials--Conservation and restoration
Library materials--Conservation and restoration--United States.
Princeton subject headings:
Computer files--United States--Conservation and restoration.
Library materials--United States--Conservation and restoration.