Columbia subject headings:
Harvard subject headings:
Opera--Europe--19th century.
Verdi, Giuseppe, 1813-1901.
Werfel, Franz, 1890-1945--Criticism and interpretation.
Princeton subject headings:
Opera--Europe--19th century.
Verdi, Giuseppe, 1813-1901.
Werfel, Franz, 1890-1945--Criticism and interpretation.