DZYUBENKO, H. A.; ZALIZKO, V. D. Pointwise Estimates for the Coconvex Approximation of Differentiable Functions. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 57, n. 1, p. 47–59, 2005. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3573. Acesso em: 5 dec. 2025.