Columbia subject headings:
Bohai (Kingdom)--History.
Korea--History--To 935.
Harvard subject headings:
Bohai (Kingdom)--History.
Korea--History--To 935.
Princeton subject headings:
Bohai (Kingdom)--Civilization.
Bohai (Kingdom)--Foreign relations--East Asia.
Bohai (Kingdom)--History.
Bohai (Kingdom)--Politics and government.