KRUTIGOLOVA , E. K. Properties of the series of exponents whose indices have finite density. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 43, n. 2, p. 277–281, 2025. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/9370. Acesso em: 6 dec. 2025.