GROZDINSKA, ​ W. A. Dudek, I. ON IDEALS IN REGULAR n-SEMIGROUPS. Matematichki Bilten, [S. l.], v. 28, n. 1, 1978. Disponível em: https://bilten.smm.org.mk/index.php/bilten/article/view/1396. Acesso em: 13 jun. 2026.