1. Abdullah, R. N. (2009). Self esteem, gender and academic achievement of undergraduate students. American Journal of Scientific Research, 3(3), 26–37.
2. Allen, J. D. (2005). Grades as valid measures of academic achievement of classroom learning. The Clearing House: A Journal of Educational Strategies, Issues and Ideas, 78(5), 218–223. https://doi.org/10.3200/tchs.78.5.218-223
3. Alokan, F. B., Ogunsanmi, O. J., Makinde, V. I., & Fashina, B. O. (2014). Influence of self-esteem on academic performance among secondary school students. IOSR Journal of Research & Method in Education (IOSRJRME), 4(5), 48–51. https://doi.org/10.9790/7388-04564851
4. Altindag, D. T., & Xu, J. (2005). The Impact of Institutions and Development on Happiness. 8. http://bus.lsu.edu/McMillin/Working_Papers/pap09_17.pdf
5. Anand, P. (2016). Happiness, well-being and human development: The case for subjective measures. Human development report background paper, July, 36. http://hdr.undp.org/sites/default/files/anand_template_rev.pdf