Columbia subject headings:
Labor unions--Political activity--Italy--History--20th century.
Socialism--Italy--History--20th century.
Harvard subject headings:
Labor unions--Political activity--Italy--History--20th century.
Socialism--Italy--20th century.
Socialism--Italy--History--20th century
Princeton subject headings:
Labor unions--Italy--Political activity--History--20th century.
Socialism--Italy--History--20th century.