SHEHU SIDI , Abubakar; MOHD, Mohd Hafiz. Bifurcation Analysis of a Modified SIR-Based COVID-19 Model with Nonlinear Incidence and Recovery Rates. MATEMATIKA, [S. l.], v. 41, n. 3, p. 375–387, 2025. DOI: 10.11113/matematika.v41.n3.1703. Disponível em: https://matematika.utm.my/index.php/matematika/article/view/1703. Acesso em: 15 feb. 2026.