Columbia subject headings:
Archaeological geology--Netherlands--Limburg.
Architecture--Conservation and restoration--Netherlands--Limburg.
Architecture--Netherlands--Limburg.
Harvard subject headings:
Archaeological geology--Netherlands--Limburg.
Architecture--Conservation and restoration--Netherlands--Limburg.
Architecture--Netherlands--Limburg.
Princeton subject headings:
Archaeological geology--Netherlands--Limburg.
Architecture--Conservation and restoration--Netherlands--Limburg.
Architecture--Netherlands--Limburg.