The Lancet Regional Health Noviembre 2021 "The income gradient in COVID-19 mortality and hospitalisation: An observational study with social security administrative records in Mexico" Eva O. Arceo-Gomez, Raymundo M. Campos-Vazquez, Gerardo Esquivel, Eduardo Alcaraz, Luis A. Martinez, Norma G. Lopez doi.org/10.1016/j.lana.2021.100115
