M. Ortega Mamani, C.A. Castaneda Olivera, E. Benites-Alfaro, Air Deterioration Gases in the Social Confinement Period by Covid-19 in Bogotá, Quito, Lima, Santiago De Chile and Buenos Aires, Chemical Engineering Transactions. 91 (2022) 457-462. doi:10.3303/CET2291077.