Columbia subject headings:
Church architecture--Germany--Cologne.
Cologne (Germany)--Antiquities.
Excavations (Archaeology)--Germany--Cologne.
Harvard subject headings:
Church architecture--Germany--Cologne.
Cologne (Germany)--Antiquities.
Excavations (Archaeology)--Germany--Cologne.
Kölner Dom.
Princeton subject headings:
Church architecture--Germany--Cologne.
Cologne (Germany)--Antiquities.
Excavations (Archaeology)--Germany--Cologne.