U. E. Etukudo and A. C. Nwokocha, “An Integral Approach for Computation of Cost-Benefit and Returns to Investment in Education”, JESR, vol. 1, no. 2, p. 57, Sep. 2011, Accessed: Mar. 10, 2026. [Online]. Available: https://www.richtmann.org/journal/index.php/jesr/article/view/11715