Columbia subject headings:
Harvard subject headings:
Boris Fyodorovich Godunov, Czar of Russia, 1551 or 1552-1605--Drama.
Operas--Librettos
Princeton subject headings:
Boris Fyodorovich Godunov, Czar of Russia, 1551 or 1552-1605--Drama.
Librettos.
Operas--Librettos.