Modeling the Impact of Susceptibility Heterogeneity in Diphtheria Outbreaks within a Vaccinated Population Using Fractional-Order Dynamics. Journal of Prime Research in Mathematics, [S. l.], v. 22, n. 2, p. 50–81, 2026. Disponível em: https://jprm.sms.edu.pk/index.php/jprm/article/view/458. Acesso em: 10 jun. 2026.