Siebert, f. S. (1956). Four theories of the press: The authoriatarian, libertarian, social responsibility, and Soviet communist concepts of what the press should be and do. University of Illinois Press.
Chicago-referens (17:e uppl.)Siebert, frederick Seaton. Four Theories of the Press: The Authoriatarian, Libertarian, Social Responsibility, and Soviet Communist Concepts of What the Press Should Be and Do. Urbana: University of Illinois Press, 1956.
MLA-referens (9:e uppl.)Siebert, frederick Seaton. Four Theories of the Press: The Authoriatarian, Libertarian, Social Responsibility, and Soviet Communist Concepts of What the Press Should Be and Do. University of Illinois Press, 1956.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.