DZYUBENKO, G. A. An interpolatory estimate for copositive polynomial approximations of continuous functions. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 74, n. 4, p. 496–506, 2022. DOI: 10.37863/umzh.v74i4.7103. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/7103. Acesso em: 7 apr. 2025.