Columbia subject headings:
Architecture--Germany--Cologne--History--20th century--Exhibitions.
City planning--Germany--Cologne--History--20th century--Exhibitions.
Cologne (Germany)--Buildings, structures, etc.--Exhibitions.
Harvard subject headings:
Architecture--Germany--Cologne--20th century.
Architecture--Germany--History--20th century
City planning--Germany--Cologne.
Cologne (Germany)--Buildings, structures, etc.
Princeton subject headings:
Architecture--Germany--Cologne--20th century--Exhibitions.
City planning--Germany--Cologne--History--20th century--Exhibitions.
Cologne (Germany)--Buildings, structures, etc.--Exhibitions.