SIEBERT, F. S. (1963). Four Theories Of The Press Fred S. Siebert, Theodore Peterson And Wilbur Schramm. University of Illinois Press.
Lua i Stíl Chicago (17ú heag.)SIEBERT, Fred S. Four Theories Of The Press Fred S. Siebert, Theodore Peterson And Wilbur Schramm. University of Illinois Press, 1963.
Lua MLA (8ú heag.)SIEBERT, Fred S. Four Theories Of The Press Fred S. Siebert, Theodore Peterson And Wilbur Schramm. University of Illinois Press, 1963.
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