Columbia subject headings:
Architecture--Europe--Congresses.
Architecture--Europe--Designs and plans.
Architecture--Europe--History--20th century--Congresses.
Architecture--Europe--History--20th century--Designs and plans.
Harvard subject headings:
Architecture, Modern--20th century--Europe--Congresses.
Architecture, Modern--20th century--Europe--Designs and plans.
Architecture--Europe--Congresses.
Architecture--Europe--Designs and plans.
Princeton subject headings:
Architecture, Modern--20th century--Europe--Congresses.
Architecture, Modern--20th century--Europe--Designs and plans.
Architecture--Europe--Congresses.
Architecture--Europe--Designs and plans.