Columbia subject headings:
Historic buildings--Conservation and restoration--Portugal.
Historic buildings--Conservation and restoration--Spain.
Stone buildings--Conservation and restoration--Portugal.
Stone buildings--Conservation and restoration--Spain.
Harvard subject headings:
Historic buildings--Conservation and restoration--Portugal.
Historic buildings--Conservation and restoration--Spain.
Stone buildings--Conservation and restoration--Portugal.
Stone buildings--Conservation and restoration--Spain.
Princeton subject headings:
Historic buildings--Conservation and restoration--Portugal.
Historic buildings--Conservation and restoration--Spain.
Stone buildings--Conservation and restoration--Portugal.
Stone buildings--Conservation and restoration--Spain.