Columbia subject headings:
Donizetti, Gaetano, 1797-1848--Criticism and interpretation.
Verdi, Giuseppe, 1813-1901--Criticism and interpretation.
Harvard subject headings:
Donizetti, Gaetano, 1797-1848--Criticism and interpretation.
Verdi, Giuseppe, 1813-1901--Criticism and interpretation.
Princeton subject headings: