Columbia subject headings:
Harvard subject headings:
China--History--Han dynasty, 202 B.C.-220 A.D.
China--History--Qin dynasty, 221 B.C.-207 B.C.
China--History--To 221 B.C.
Princeton subject headings:
China--History--221 B.C.
China--History--Han dynasty, 202 B.C.-220 A.D.
China--History--Qin dynasty, 221-207 B.C.