SEVOST'YANOV, E. A. Generalization of one Poletskii lemma to classes of space mappings. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 61, n. 7, p. 969–975, 2009. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3071. Acesso em: 5 dec. 2025.