Columbia subject headings:
Harvard subject headings:
Astronomy, Chinese--History
Calendar, Chinese--Hisotry.
China--Civilization--To 221 B.C.
China--History--To 221 B.C.
Princeton subject headings:
Astronomy, Chinese--History.
Calendar, Chinese--Hisotry.
China--Civilization--To 221 B.C.
China--History--To 221 B.C.