ZHUCHOK, A. V. Semiretractions of Trioids. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 66, n. 2, p. 195–207, 2014. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2123. Acesso em: 14 apr. 2025.