Permanence of an SIR epidemic model with density dependent birth rate and distributed time delay

Global Hopf bifurcation analysis of an susceptible-infective-removed epidemic model incorporating media coverage with time delay

“…For instance, it can change the stability of equilibrium and thus lead to periodic solutions by Hopf bifurcation [6,[10][11][12]14,17,18,21,[27][28][29][30].…”