1. Akpan E 1990. Strategies of content analysis. In: E Akpan (Ed.): Communication Arts: Principles, Applications, Practices. Uyo: Modern Business Press Ltd.
2. Babbie E 2001. The Practice of Social Research. 9th Edition. California: Wadsworth/Thomson Learning, P. 204.
3. Baran S J, Davis D K 1995. Mass Communication Theory: Foundations, Ferment, and Future. California: Wadsworth Publishing Company, P. 104.
4. Berelson B 1952. Analysis of Communication Research. Glencoe, Illinois: Free Press.
5. McQuail D 2005. Mc Quail’s Mass Communication Theory. 5th Edition. London: Sage Publications Ltd., P. 363.