APA Style

Siebert, F, S., Peterson, T, &, S, W. (1956). Four theories of the press : the authoritarian, libertarian, social responsibility, and soviet communist concepts of what the press should be and do . Urbana: University of Illinois Press.

MLA Style

Siebert, Fred, S.., Peterson, Theodore, &, Schramm,, Wilbur. "Four theories of the press : the authoritarian, libertarian, social responsibility, and soviet communist concepts of what the press should be and do". Urbana: University of Illinois Press, 1956. Text.