Okopi, Fidel, and Jeremiah J. O. Obera. 2021. “Applying Dual Flexible Open Schooling System to Universal Basic Education: A Panacea for Accomplishing Sustainable Development Goal 4 in Nigeria”. West African Journal of Open and Flexible Learning 10 (1):99-118. https://wajofel.org/index.php/wajofel/article/view/86.