On Ext and Hyperext groups in the category of functors. Gulf Journal of Mathematics, [S. l.], v. 20, n. 2, p. 1–12, 2025. DOI: 10.56947/gjom.v20i2.3211. Disponível em: https://gjom.org/index.php/gjom/article/view/3211. Acesso em: 12 sep. 2026.