Columbia subject headings:
Italy--Politics and government--19th century--Congresses.
Italy--Politics and government--20th century--Congresses.
Socialism--Italy--History--Congresses.
Harvard subject headings:
Italy--Politics and government--19th century--Congresses.
Italy--Politics and government--20th century--Congresses.
Socialism--Italy--Congresses
Socialism--Italy--History--Congresses.
Princeton subject headings:
Italy--Politics and government--19th century--Congresses.
Italy--Politics and government--20th century--Congresses.
Socialism--Italy--History--Congresses.