ANDRIYUK, E. P. On extension of continuous functions defined on a circle. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 56, n. 8, p. 1011–1017, 2004. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3818. Acesso em: 11 apr. 2025.