Columbia subject headings:
Harvard subject headings:
Censorship--Portugal--History--20th century--Sources.
Journalism--Portugal--History--20th century--Sources.
Newspapers--Portugal--History--20th century--Sources.
Portuguese newspapers--History--20th century--Sources.
Princeton subject headings:
Censorship--Portugal--History--20th century--Sources.
Journalism--Portugal--History--20th century--Sources.
Newspapers--Portugal--History--20th century--Sources.