Madge Escobedo, J., and J. R. Pérez Núñez. “Analysis and Simulation of an Extended SEIR Mathematical Model With Vaccination for the Spread of SARS-COV-2”. Selecciones Matemáticas, vol. 9, no. 01, July 2022, pp. 121 -36, doi:10.17268/sel.mat.2022.02.09.