Bernoussi, Amine. “Bifurcation of Periodic Solutions of a Delayed SEIR Epidemic Model With Nonlinear Incidence Rate”. Journal of Applied Nonlinear Dynamics 10, no. 3 (September 1, 2021): 351–367. Accessed October 17, 2026. https://lhscientificpublishing.com/index.php/jand/article/view/566.