Columbia subject headings:
Fortification--Japan--History--To 1500.
Japan--Capital and capitol--History--To 1500.
Japan--History--To 794.
Harvard subject headings:
Fortification--Japan--History.
Japan--Capital and capitol--History.
Japan--History--To 794.
Princeton subject headings:
Fortification--Japan--History.
Japan--Capital and capitol--History.
Japan--History--To 794.