1Sunstein,Cass R. , Republic. com, Princeton, NJ: Princeton University Press, 2001.
2MacKuen,Michael, "Speaking of Politics: Individual Conversational Choice, Public Opinion, and the Prospects for Deliberative Democracy", in John A. Ferejohn and James H. Kuklinski eds. , Information and Democratic Processes, Urbana: University of Illinois Press,1990, p. 60.
3Huckfeldt, Robert R. and Sprague, John, Citizens, Politics, and Social Communication, Cambridge, MA: Cambridge University Press, 1995.
4Rogers, Everett M. and Kincaid, D. Lawrence, Free Press, Communication Network: Toward a New Paradigm for Research, New York: 1981.
5McPherson, M. , Smith-Lovin, L. and Cook, J.M. , " Birds of a Feather: Homophily in Social Networks," Annual Review of Sociology, 27, 2001, pp. 415 - 444.
6Downs,Anthony, An Economic Theory of Democracy, New York : Harper & Brothers, 1957.
7Rosenberg,Morris, "Some Determinants of Political Apathy", Public Opinion Quarterly, 18, 4, 1954, pp. 349 -366.
8Noelle-Neumann, Elisabeth, Offentliche Meinung : Die Entdeckung Der Schweigespirale , Frankfurt: Ullstein, 1989.
9Wyatt,Robert O. , Katz, Elihu, Levinsohn, Hanna and A1-Haj, Majid, "The Dimensions of Expression Inhibition: Perceptions of Obstacles to Free Speech in Three Cultures," International Journal of Public Opinion Research 8, 3, 1996, pp. 229-47.
10Wyatt, Robert O., Kim, Joohan and Katz, Elihu, " How Feeling Free to Talk Affects Ordinary Political Conversation, Purposeful Argumentation, and Civic Participation," Journalism and Mass Communications Quarterly 77, 1, 2000, pp. 99 - 114.
