GRIGOROV, Tsvetko Vasilev. COVID-19: History, Etiology, Epidemiology, and Pathogenesis. American Scientific Research Journal for Engineering, Technology, and Sciences, Jordan, v. 92, n. 1, p. 153–159, 2023. Disponível em: https://www.asrjetsjournal.org/American_Scientific_Journal/article/view/8671. Acesso em: 13 oct. 2025.