Columbia subject headings:
Harvard subject headings:
Architecture--Conservation and restoration--20th century.
Buildings--Germany--Cologne.
Buildings--Repair and reconstruction--20th century.
Cologne (Germany)--Haus Gürzenich.
Concerts--Documentation--Germany--Cologne.
Gürzenich (Cologne, Germany)--History.
Music-halls--Documentation--Germany--Cologne.
Princeton subject headings:
Concerts--Germany--Cologne.
Gürzenich (Cologne, Germany)
Music-halls--Germany--Cologne.