A STUDY ON SOME SUBSTRUCTURES OF ORDERED MULTISETS. FUDMA JOURNAL OF SCIENCES, [S. l.], v. 2, n. 1, p. 201–205, 2023. Disponível em: http://www.fjsadmin.fudutsinma.edu.ng/index.php/fjs/article/view/1297. Acesso em: 11 sep. 2025.