Carvalho, P. M., Soares, S. C., & Castro, A. R. (2021). What did we learn after the 2020 pandemic? Seroprevalence of SARS-CoV-2 infection in a North region of Portugal during 3rd lockdown. International Journal of Research in Medical Sciences, 9(9), 2568–2572. https://doi.org/10.18203/2320-6012.ijrms20213393