“Use of Filters and Special Materials in Classrooms, Based on the Assessment of the Presence of CO2 As an Indicator of Covid Reduction and Control in Closed Spaces = Uso De Filtros Y Materiales Especiales En Aulas, Basado En La evaluación De Presencia De CO2 Como Indicador De reducción Y Control De Covid En Espacios Cerrados”. Building & Management, vol. 5, no. 3, Dec. 2021, pp. 51-62, https://doi.org/10.20868/bma.2021.3.4714.