Abdeen, M.A.R. , Sheltami, T.R. and Nemer, I.A. (2021) “An approximate analytical formula for estimating the weight of factors affecting the spread of COVID-19: a case study of the first wave”, Revista do Instituto de Medicina Tropical de São Paulo, 63, p. e45. doi:10.1590/S1678-9946202163045.