Columbia subject headings:
Harvard subject headings:
Machine-readable bibliographic data--Congresses.
Online library catalogs--Congresses.
Recataloging--Data processing--Congresses.
Retrospective conversion (Cataloging)--Congresses.
Princeton subject headings:
Machine-readable bibliographic data--Congresses.
Online library catalogs--Congresses.
Recataloging--Data processing--Congresses.
Retrospective conversion (Cataloging)--Congresses.