Columbia subject headings:
Harvard subject headings:
Japan--History--To 1333.
Japan--Relations--Korea.
Korea--History--Koryŏ period, 935-1392.
Korea--Relations--Japan.
Princeton subject headings:
Japan--History--To 1333.
Japan--Relations--Korea.
Korea--History--Koryŏ period, 935-1392.
Korea--Relations--Japan.