Columbia subject headings:
Partito socialista italiano--History.
Socialism--Italy--History--20th century.
Harvard subject headings:
Partito socialista italiano--History.
Socialism--Italy--20th century.
Socialism--Italy--History--20th century
Princeton subject headings:
Partito socialista italiano--History.
Political parties--Italy--History--20th century.
Socialism--Italy--History--20th century.