Columbia subject headings:
Harvard subject headings:
Architecture--Conservation and restoration--Germany--North Rhine-Westphalia--Periodicals.
Architecture--Germany--North Rhine-Westphalia--Periodicals.
Art--Conservation and restoration--Germany--North Rhine-Westphalia--Periodicals.
Art--Germany--North Rhine-Westphalia--Periodicals.
Monuments--Conservation and restoration--Germany--North Rhine-Westphalia--Periodicals.
Princeton subject headings:
Architecture--Germany (West)--North Rhine-Westphalia--Conservation and restoration--Periodicals.
Architecture--Germany (West)--North Rhine-Westphalia--Periodicals.
Art--Conservation and restoration--Germany (West)--North Rhine-Westphalia--Periodicals.
Art--Germany (West)--North Rhine-Westphalia--Periodicals.
Monuments--Germany (West)--North Rhine-Westphalia--Conservation and restoration--Periodicals.