Columbia subject headings:
American literature--20th century--Censorship.
American literature--20th century--Political aspects.
Authors, American--20th century--Political and social views.
Censorship--United States--History--20th century.
Police patrol--United States--Surveillance operations.
Politics and literature--United States--History--20th century.
United States. Central Intelligence Agency.
United States. Federal Bureau of Investigation.
Harvard subject headings:
American literature--20th century--Censorship.
American literature--20th century--History and criticism
American literature--20th century--Political aspects.
Authors, American--20th century--Political and social views
Censorship--United States--History--20th century.
Police patrol--United States--Surveillance operations.
Politics and literature--United States--History--20th century.
United States. Central Intelligence Agency
United States. Federal Bureau of Investigation
Princeton subject headings:
American literature--20th century--Censorship.
American literature--20th century--Political aspects.
Authors, American--20th century--Political and social views.
Censorship--United States--History--20th century.
Police patrol--United States--Surveillance operations.
Politics and literature--United States--History--20th century.
United States. Central Intelligence Agency
United States. Federal Bureau of Investigation