COVID-19: Frequency of positive cases in healthcare professionals at a reference hospital in Paraná. Research, Society and Development, [S. l.], v. 10, n. 9, p. e5310917662, 2021. DOI: 10.33448/rsd-v10i9.17662. Disponível em: https://rsdjournal.org/rsd/article/view/17662. Acesso em: 5 dec. 2025.