Columbia subject headings:
Socialism--Italy--Parma--History.
Socialists--Italy--Parma--History.
Harvard subject headings:
Socialism--Italy--Parma--History.
Socialism--Italy--Parma.
Socialists--Italy--Parma--History.
Princeton subject headings:
Socialism--Italy--Parma--History.
Socialists--Italy--Parma--History.