Columbia subject headings:
Greece--History.
History, Ancient.
Harvard subject headings:
Croesus, King of Lydia, active 560 B.C.-546 B.C.
Cyrus, the Great, King of Persia, -530 B.C. or 529 B.C.
Greece--History.
History, Ancient.
Iran--History--To 640.
Lydia (Kingdom)
Princeton subject headings:
Greece--History.
History, Ancient.