ZHAO, Dr. Bin. Differential equation analysis on COVID-19. Journal of Medical Care Research and Review, [S. l.], v. 4, n. 5, 2021. DOI: 10.15520/mcrr.v4i5.133. Disponível em: http://mcrr.info/index.php/mcrr/article/view/133. Acesso em: 8 jan. 2025.