Karkri, Jaafar El, and Khadija Niri. “Monotone Dynamical Systems Theory for Epidemiological Models With Delay: A New Approach With Applications”. Discontinuity, Nonlinearity, and Complexity, vol. 8, no. 4, Aug. 2026, pp. 369-77, https://doi.org/10.5890/DNC.2019.12.002.