Columbia subject headings:
Harvard subject headings:
China--Economic conditions--To 1644.
China--Politics and government--960-1279.
Korea--Officials and employees--History.
Korea--Politics and government--935-1392.
Princeton subject headings:
China--Economic conditions--To 1644.
China--Politics and government--960-1279.
Korea--Officials and employees--History.
Korea--Politics and government--935-1392.