AHMAD, S.; QIU, D.; RAHMAN, M. ur. Dynamics of a fractional-order COVID-19 model under the nonsingular kernel of Caputo-Fabrizio operator. Mathematical Modelling and Numerical Simulation with Applications, [S. l.], v. 2, n. 4, p. 228–243, 2022. DOI: 10.53391/mmnsa.2022.019. Disponível em: https://mmnsa.org/index.php/mmnsa/article/view/51. Acesso em: 24 nov. 2024.