1. Butler HG 2006. A Framework for Course Design in Academic Writing for Tertiary Education. PhD Thesis, Unpublished. Pretoria: University of Pretoria.
2. Cohen J 1988. Statistical Power and Analysis for the Behavioural Sciences. 2nd Edition. Hillsdale, NJ: Lawrence Erlbaum Associates.
3. Dornyei Z 2007. Research Methods in Applied Linguistics. Oxford: Oxford University Press.
4. Gee JP 1990. Social Linguistics and Literacies: Ideology in Discourses. London: Falmer Press.
5. Gee JP 1996. Social Linguistics and Literacies: Ideology in Discourses. 2nd Edition. London: Taylor and Francis.