OKREGLICKI, A. Answer to ECG Quiz no.18. SA Heart Journal, [S. l.], v. 7, n. 1, p. 62–63, 2017. DOI: 10.24170/7-1-1970. Disponível em: https://www.journals.ac.za/SAHJ/article/view/1970. Acesso em: 8 oct. 2025.