ENDIMIONI, G. Hopficity and Co-Hopficity in Soluble Groups. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 56, n. 10, p. 1335–1341, 2004. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3846. Acesso em: 6 dec. 2025.