López, Lucy, Walter Portugal, Karen Huamán, and Cristian Obregón. 2022. “Effectiveness of COVID-19 Vaccines and Mortality Risk in Peru: A Population-Based Study of Matched Cohorts”. Anales De La Facultad De Medicina 83 (2): 87-94. https://doi.org/10.15381/anales.v83i2.21531.