BANAKH, T.O.; GAVRYLKIV, V.M. Extending binary operations to funtor-spaces. Carpathian Mathematical Publications, [S. l.], v. 1, n. 2, p. 114–127, 2009. Disponível em: https://scijournals.pnu.edu.ua/index.php/cmp/article/view/2576. Acesso em: 4 may. 2024.