OSTAPENKO, V. V. To the problem of continuity of many-valued mappings. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 47, n. 11, p. 1519–1525, 1995. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5542. Acesso em: 5 dec. 2025.