Columbia subject headings:
Harbors--Japan--Japan Sea Coast--History--16th century.
Merchant marine--Japan--Japan Sea Coast--History--16th century.
Shipping--Japan--Japan Sea Coast--History--16th century.
Harvard subject headings:
Harbors--Japan--History.
Merchant marine--Japan--History
Shipping--Japan--History
Princeton subject headings:
Harbors--Japan--History.
Merchant marine--Japan--History.
Shipping--Japan--History.