MILLAR, R. S. Answer to ECG Quiz no. 31. SA Heart Journal, [S. l.], v. 10, n. 3, p. 546–549, 2017. DOI: 10.24170/10-3-1798. Disponível em: https://www.journals.ac.za/SAHJ/article/view/1798. Acesso em: 8 oct. 2025.