A Note on $Card(X)$. Analysis in Theory and Applications, [S. l.], v. 36, n. 4, p. 468–481, 2020. DOI: 10.4208/ata.OA-SU4. Disponível em: https://www.global-sci.com/index.php/ata/article/view/8205. Acesso em: 5 dec. 2025.