1. Adegboye, A. O. (1993). Proficiency in English language as a factor contributing to competency in Mathematics. Education Today, 6(2), 9-13.
2. Benrabah, M. (2007). Language in Education Planning in Algeria:Historical Development and Current Issues. In Language Policy. (2007)6; 225-252. Springer.
3. Council of Europe. (2001). Common European framework of reference for languages: Learning, teaching, assessment. Cambridge, U.K: Press Syndicate of the University of Cambridge.
4. Clark, R. C. (2002). The New ISD: Applying Cognitive Strategies to Instructional Design. ISPI Performance Improvement Journal, 41(7), 10-16. doi:10.1002/pfi.4140410704
5. Coleman, H. (2010). The English Language in Development. A paper commissioned by the British Council. Retrieved on Dec 9, 2014 from https://www.teachingenglish.org. uk/sites/teacheng/files/UK011-English-Language-Development.pdf