BABENKO, V. F.; PARFINOVYCH, N. V. On the order of relative approximation of classes of differentiable periodic functions by splines. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 62, n. 2, p. 147–157, 2010. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2851. Acesso em: 7 apr. 2025.