Columbia subject headings:
Communism--Italy--History--20th century.
De Martino, Ernesto, 1908-1965--Correspondence.
Secchia, Pietro--Correspondence.
Harvard subject headings:
Communism--Italy--History--20th century
De Martino, Ernesto, 1908-1965--Correspondence.
Secchia, Pietro--Correspondence.
Princeton subject headings:
Communism--Italy--History--20th century.
De Martino, Ernesto, 1908-1965--Correspondence.
Secchia, Pietro--Correspondence.