Columbia subject headings:
Harvard subject headings:
Operas--20th century--Librettos.
Operas--Librettos
Palestrina, Giovanni Pierluigi da, 1525?-1594--Drama.
Princeton subject headings:
Drama.
Librettos.
Operas--Librettos.
Palestrina, Giovanni Pierluigi da, 1525?-1594--Drama.