BONDAR’, E. A. Semigroups of Strong Endomorphisms of Infinite Graphs and Hypergraphs. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 65, n. 6, p. 743–754, 2013. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2459. Acesso em: 5 dec. 2025.