DUNDUCHENKO, L. E. On non-emptiness of one class of functions analytical in a finite-connected circular domain . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 23, n. 4, p. 454–463, 1971. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8579. Acesso em: 6 dec. 2025.