THE SOLUTION OF A MATHEMATICAL MODEL FOR COVID-19 TRANSMISSION AND VACCINATION IN NIGERIA BY USING A DIFFERENTIAL TRANSFORMATION METHOD. FUDMA JOURNAL OF SCIENCES, [S. l.], v. 6, n. 5, p. 50–56, 2022. DOI: 10.33003/fjs-2022-0605-1089. Disponível em: http://www.fjsadmin.fudutsinma.edu.ng/index.php/fjs/article/view/1089. Acesso em: 11 sep. 2025.