Columbia subject headings:
Agriculture--Italy--Piacenza (Province)--History--19th century.
Agriculture.
Composers--Italy--Correspondence.
Verdi, Giuseppe, 1813-1901--Homes and haunts--Italy--Sant'Agata di Villanova d'Arda.
Verdi, Giuseppe, 1813-1901.
Harvard subject headings:
Agriculture--Italy--Piacenza (Province)--History--19th century.
Composers--Italy--Correspondence
Princeton subject headings:
Agriculture--Italy--Piacenza (Province)--History--19th century.
Composers--Italy--Correspondence.