Columbia subject headings:
Harvard subject headings:
Austria--History--20th century--Congresses.
Austria--Relations--Czech Republic--Congresses.
Austria--Relations--Czechoslovakia--Congresses.
Czech Republic--History--20th century--Congresses.
Czech Republic--Relations--Austria--Congresses.
Czechoslovakia--History--20th century--Congresses.
Czechoslovakia--Relations--Austria--Congresses.
Princeton subject headings:
Austria--History--20th century--Congresses.
Austria--Relations--Czech Republic--Congresses.
Austria--Relations--Czechoslovakia--Congresses.
Czech Republic--History--20th century--Congresses.
Czech Republic--Relations--Austria--Congresses.
Czechoslovakia--History--20th century--Congresses.
Czechoslovakia--Relations--Austria--Congresses.