Columbia subject headings:
Operas--Librettos.
Operas--Scores.
Xerxes I, King of Persia, 519 B.C.-465 B.C. or 464 B.C.--Drama.
Harvard subject headings:
Operas--Librettos
Operas--Scores
Xerxes I, King of Persia, 519-465 or 464 B.C.--Drama.
Princeton subject headings:
Operas--Librettos.
Operas--Scores.
Operas.
Scores.
Xerxes I, King of Persia, 519 B.C.-465 B.C. or 464 B.C.--Drama.