Columbia subject headings:
Architecture--Germany--Cologne--Guidebooks.
Cologne (Germany)--Buildings, structures, etc.--Guidebooks.
Cologne (Germany)--Guidebooks.
Public architecture--Germany--Cologne--Guidebooks.
Harvard subject headings:
Architecture--Germany--Cologne--Guidebooks.
Cologne (Germany)--Buildings, structures, etc.--Guidebooks.
Historic buildings--Germany--Cologne.
Princeton subject headings:
Architecture--Germany--Cologne--Guidebooks.
Cologen (Germany)--Guidebooks.
Cologne (Germany)--Buildings, structures, etc.--Guidebooks.
Guidebooks.