Columbia subject headings:
Harvard subject headings:
Extinct cities--India--Kerala.
India--Antiquities, Roman.
India--Commerce--Rome.
Rome--Commerce--India.
Trade routes--Indian Ocean--History.
Trade routes--Rome--History.
Princeton subject headings:
Extinct cities--India--Kerala.
India--Antiquities, Roman.
India--Commerce--Rome.
Rome--Commerce--India.
Trade routes--Indian Ocean--History.
Trade routes--Rome--History.