Columbia subject headings:
Art, European--20th century--Congresses.
Capitals (Cities)--Europe--History--20th century--Congresses.
Harvard subject headings:
Art, European--20th century--Congresses.
Capitals (Cities)--Europe--History--20th century--Congresses.
Princeton subject headings:
Art, European--20th century--Congresses.
Capitals (Cities)--Europe--History--20th century--Congresses.