ROMANOVSKY , A. V.; SEMENTOVSKY , A. V. Existence of normal complement to the Hall subgroup . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 6, p. 851–853, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8023. Acesso em: 5 dec. 2025.