ZHUCHOK, A. V. Free dimonoids. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 63, n. 2, p. 165–175, 2011. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2708. Acesso em: 14 apr. 2025.