APPLICATION OF NON-STANDARD FINITE DIFFERENCE METHOD ON COVID-19 MATHEMATICAL MODEL WITH FEAR OF INFECTION. FUDMA JOURNAL OF SCIENCES, [S. l.], v. 7, n. 4, p. 357–368, 2023. DOI: 10.33003/fjs-2023-0704-1933. Disponível em: http://www.fjsadmin.fudutsinma.edu.ng/index.php/fjs/article/view/1933. Acesso em: 11 sep. 2025.