Columbia subject headings:
Harvard subject headings:
Architecture--Italy--Palermo--Archival resources--Congresses.
Architecture--Italy--Palermo--Congresses.
Architecture--Italy--Palermo--History--Sources--Congresses.
Princeton subject headings:
Architecture--Italy--Palermo--Archival resources--Congresses.
Architecture--Italy--Palermo--Archives--Congresses.
Architecture--Italy--Palermo--History--Sources--Congresses.