LASURIYA, R. A. Structural properties of functions defined on a sphere on the basis of Φ-strong approximation. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 58, n. 1, p. 20–25, 2006. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3431. Acesso em: 5 dec. 2025.