Columbia subject headings:
Composers--Italy--Correspondence.
Opera--Italy--19th century.
Ponchielli, Amilcare, 1834-1886--Correspondence.
Harvard subject headings:
Composers--Italy--Correspondence
Opera--Italy--19th century
Ponchielli, Amilcare, 1834-1886--Correspondence.
Princeton subject headings:
Composers--Italy--Correspondence.
Opera--Italy--19th century.
Ponchielli, Amilcare, 1834-1886--Correspondence.