Columbia subject headings:
Architecture--Italy--Castelporziano.
Art--Italy--Castelporziano.
Castelporziano (Italy)--Pictorial works.
Harvard subject headings:
Architecture--Italy--Castel Porziano.
Art--Italy--Castel Porziano.
Castello di Castel Porziano.
Castelporziano (Italy)--Pictorial works.
Princeton subject headings:
Architecture--Italy--Castel Porziano.
Art--Italy--Castel Porziano.
Castel Porziano (Italy)--Pictorial works.