SEIR model for COVID-19: stability of the standard coronavirus factor and control mechanismSalah Boulaaras, Ramesh Ramalingam and Arul Joseph GnanaprakasamEur. Phys. J. Spec. Top., 232 14-15 (2023) 2485-2495DOI: https://doi.org/10.1140/epjs/s11734-023-00915-4