Columbia subject headings:
Harvard subject headings:
Cao, Cao, 155-220
China--History--Han dynasty, 202 B.C.-220 A.D.
Yuan, Shao, 154?-202
Princeton subject headings:
Cao, Cao, 155-220.
China--History--Han dynasty, 202 B.C.-220 A.D.
China--History--Three kingdoms, 220-265--Biography.
Yuan, Shao, 154?-202.