1. Azina, I. N., & Halimah, A. (2012). Student factors and mathematics achievement: evidence from TIMSS 2007. Eurasia Journal of Mathematics, Science and Technology Education, 8(3), 249–255.
2. Coleman, J. S., Campbell, E. Q., Hobson, C. J., McPartland, J., Mood, A. M., Weinfield, F. D., & York, R. L. (1966). Equality of educational opportunity. Washington DC: Government Printing Office.
3. Dahlan, N. A., Noor, N. A. M., Mustafa, S. M. S., Hashim, K. S., & Zulkifli, V. (2010). Exploring the gender gap in achievement in Malaysia: a case for learning style. The International Journal of Learning, 17(4), 15–27.
4. Department of Statistics Malaysia (2015) The Source of Malaysia’s Official Statistics. Retrieved September 28, 2015, from http://www.statistics.gov.my/portal/index.php .
5. Fennema, E., & Shermann, J. (1977). Sex-related differences in mathematics achievement, spatial visualization and affective factors. American Educational Research Journal, 14(1), 51–71. doi: 10.3112/00028312014001051 .