Guerra-Centeno, D., Burmester-Ruiz, L., Guerra-Burmester, P., Guerra-Burmester, D., & Villatoro-Paz, F. (2020). Voluntary and mandatory use of face mask by pedestrians in Guatemala City during the COVID-19 pandemic. Ciencia, Tecnologí­a Y Salud, 7(3), 477–482. https://doi.org/10.36829/63CTS.v7i3.894