Investigating the dynamics of a delayed stage-structured epidemic model with saturated incidence and treatment functionsSoumen Kundu, Hebatallah J. Alsakaji, Fathalla A. Rihan, Sarit Maitra and Ranjit Kumar UpadhyayEur. Phys. J. Plus, 137 1 (2022) 171DOI: https://doi.org/10.1140/epjp/s13360-022-02351-0