1. Babbie E, Mouton J 2010. The Practice of Social research. Cape Town: Oxford University Press.
2. Bandura A 1986. Social Foundations of Thought and Action: A Social Cognitive Theory. Englewood Cliffs, NJ: Prentice-Hall.
3. Bandura A 1997. Self-efficacy in Changing Societies. New York: Cambridge University Press.
4. Bryman A, Cramer D 1990. Quantitative Data Analysis for Social Scientists. London: Routledge.
5. Cohen C, Manion L, Morrison K 2007. Research Methods in Education. New York: Routledge.