Idempotent elements of the semigroup B_X (D) defined by semilattice of the class ∑_2(X,5) . MCIT: Proceedings of International scientific and practical conference, [S. l.], n. 8, p. 441–443, 2025. DOI: 10.31713/MCIT.2025.136. Disponível em: https://mcitdoc.org.ua/index.php/ITConf/article/view/759. Acesso em: 2 apr. 2026.