Okoye, C., M. B. Okofu, B. I D, N. K. Nubila, C. L. . Ejikeme, S. N. Aguegboh, D. F. Agbebaku, and G. C. E. Mbah. “A MATHEMATICAL APPROACH TO UNDERSTANDING THE EFFECTIVENESS OF CONTROL MEASURES IN MITIGATING CORONAVIRUS DISEASE 19 (COVID-19) SPREAD”. Academic Journal of Statistic and Mathematics, vol. 7, no. 10, Oct. 2021, pp. 14-22, http://cirdjournals.com/index.php/ajsm/article/view/120.