Susanto, H.; Tjahjono, V.; Hasan, A.; Kasim, M.; Nuraini, N.; Putri, E.; Kusdiantara, R.; Kurniawan, H. How Many Can You Infect? Simple (and Naive) Methods of Estimating the Reproduction Number. Commun.Biomath.Sci. 2020, 3, 28-36.