Columbia subject headings:
Communism--Soviet Union--History--20th century.
Communism.
Soviet Union--Foreign relations--1953-1975.
World politics--1955-1965.
Harvard subject headings:
Communism--1945-
Communism--Soviet Union--History
Partito socialista italiano.
Soviet Union--Foreign relations--1953-1975.
World politics--1955-1965
Princeton subject headings:
Italy--Politics and government--1945-1976.
Partito socialista italiano--History--20th century.
Socialism--Italy--History--20th century.