MARKOVSKI, G. Čupona, S. VECTOR VALUED GROUPOIDS INDUCED BY VARIETIES OF SEMIGROUPS. Matematichki Bilten, [S. l.], v. 14, n. 1, 1990. Disponível em: https://bilten.smm.org.mk/index.php/bilten/article/view/1478. Acesso em: 13 jun. 2026.