Columbia subject headings:
Harvard subject headings:
Milan (Italy)--History--Sources.
Partito socialista italiano di unità proletaria--History--Sources.
World War, 1939-1945--Underground movements--Italy--Milan--Sources.
Princeton subject headings:
Milan (Italy)--History--Sources.
Partito socialista italiano di unità proletaria--History--Sources.
World War, 1939-1945--Underground movements--Italy--Milan--Sources.