Columbia subject headings:
Harvard subject headings:
Opera--19th century
Opera--Germany--Biography.
Opera--Germany--Frankfurt am Main.
Opera--Italy--19th century
Verdi, Giuseppe, 1813-1901--Criticism and interpretation.
Verdi, Giuseppe, 1813-1901. Operas.
Princeton subject headings:
Frankfurter Oper.
Opera--Germany--Frankfurt am Main.
Verdi, Giuseppe, 1813-1901. Operas.