Columbia subject headings:
Dwellings--Italy--Ostia.
Italy--Antiquities.
Ostia (Italy)--Antiquities.
Ostia (Italy)--Social conditions.
Harvard subject headings:
Ostia (Italy)--Antiquities.
Ostia (Italy)--Homes and haunts.
Princeton subject headings:
Apartment houses--Italy--Ostia (Extinct city).
Dwellings--Italy--Ostia (Extinct city).
Italy--Antiquities.
Ostia (Extinct city)--Social conditions.