Anyanwu, M. C., S. N. Neossi-Nguetchue, G. M. Moremedi, and A. S. Eegunjobi. “Mathematical Model and Optimal Control of Covid-19 in Nigeria”. Earthline Journal of Mathematical Sciences, Vol. 14, no. 3, Mar. 2024, pp. 421-4, doi:10.34198/ejms.14324.421441.