KASANA, Kh. S. Existence theorem for refined order of analytical functions . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 40, n. 1, p. 117–121, 1987. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/9068. Acesso em: 5 dec. 2025.