PROTASOV, I. V. Irresolvable left topological groups. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 52, n. 6, p. 758–765, 2000. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4470. Acesso em: 7 apr. 2025.