NAVASARDYAN, Shant. Independence of the axioms of hypergroup over the group. Armenian Journal of Mathematics, Yerevan, Armenia, v. 13, n. 12, p. 1–11, 2021. DOI: 10.52737/18291163-2021.13.12-1-11. Disponível em: https://armjmath.sci.am/index.php/ajm/article/view/571. Acesso em: 3 apr. 2025.