ZAITSEV, D. I. On the theory of minimax groups. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 23, n. 5, p. 652–660, 1971. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8336. Acesso em: 5 dec. 2025.