Columbia subject headings:
Architecture--Italy--History.
Architecture--Spain--Barcelona--History.
City planning--Italy--Naples--History.
City planning--Spain--Barcelona.
Harvard subject headings:
Architecture--Italy--Naples--History--Congresses.
Architecture--Spain--Barcelona--History--Congresses.
Princeton subject headings:
Architecture--Italy--History.
Architecture--Spain--Barcelona--History.
City planning--Italy--Naples--History.
City planning--Spain--Barcelona.