Columbia subject headings:
China--Commerce--History--To 1500.
East Asia--Commerce--Korea.
Korea--Commerce--East Asia.
Korea--Commerce--History--To 1500.
Korea--History--Koryŏ period, 935-1392.
Harvard subject headings:
China--Commerce--History--To 1500.
East Asia--Commerce--Korea.
Korea--Commerce--East Asia.
Korea--Commerce--History--To 1500.
Korea--History--Koryŏ period, 935-1392
Princeton subject headings:
East Asia--Commerce--History.
Korea--Commerce--History--Koryŏ period, 935-1392.
Merchant marine--East Asia--History.
Merchants--Korea--Koryŏ period, 935-1392--History.