DE WITT, P.; IRUSEN, E.M.; DOUBELL, A.F. Is the heart half full or half empty?. SA Heart Journal, [S. l.], v. 6, n. 2, p. 120–121, 2017. DOI: 10.24170/6-2-2000. Disponível em: https://scriptura.journals.ac.za/index.php/SAHJ/article/view/2000. Acesso em: 12 jun. 2026.