GOL'BERG, A. L. Extremal problems in a class of mappings with bounded integral characteristics. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 52, n. 4, p. 544–547, 2000. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4444. Acesso em: 5 dec. 2025.