Columbia subject headings:
Partito della democrazia cristiana--History--Sources.
Partito della democrazia cristiana.
Terrorism--Italy--History--20th century--Sources.
Terrorism--Italy--History--20th century.
Harvard subject headings:
Partito della democrazia cristiana--History--Sources.
Partito della democrazia cristiana.
Terrorism--Italy--History--20th century
Terrorism--Italy--History--20th century--Sources.
Princeton subject headings:
Partito della democrazia cristiana--History--Sources.
Partito della democrazia cristiana.
Terrorism--Italy--History--20th century--Sources.
Terrorism--Italy--History--20th century.