BONDARENKO, I.; KRAVCHENKO, R. Schreier Graphs for a Self-Similar Action of the Heisenberg Group. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 65, n. 11, p. 1456–1462, 2013. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2525. Acesso em: 5 dec. 2025.