Columbia subject headings:
Harvard subject headings:
Archival materials--Digitization--Austria--History--Congresses.
Archives--Austria--History--Congresses.
Europe--History--Archival resources--Congresses.
Princeton subject headings:
Archival materials--Digitization--Austria--History--Congresses.
Archives--Austria--History--Congresses.
Europe--History--Archival resources--Congresses.