Columbia subject headings:
Architecture--Germany--Cologne--History.
Cologne (Germany)--Buildings, structures, etc.
Cologne (Germany)--History--Pictorial works.
Cologne (Germany)--Pictorial works.
Harvard subject headings:
Art, European.
Cologne (Germany)--History.
Cologne (Germany)--In art.
Cologne (Germany)--Pictorial works.
Princeton subject headings:
Cologne (Germany)--History.
Cologne (Germany)--In art.
Cologne (Germany)--Pictorial works.