Jimoh, S. M. ., A. Ahmed, O. H. Kehinde, and O. S. . Emmanuel. “Willingness to Pay for Covid-19 Vaccine by Frontline Health Workers in Tertiary Institutions in Nigeria”. Journal of Liaquat University of Medical & Health Sciences, vol. 21, no. 02, June 2022, pp. 143-8, http://ojs.lumhs.edu.pk/index.php/jlumhs/article/view/666.