A fractional order Covid-19 epidemic model with Mittag-Leffler kernel. Neliniini Kolyvannya, [S. l.], v. 24, n. 3, p. 378–400, 2021. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/1039. Acesso em: 21 jan. 2026.