DZYUBENKO, H. A.; GILEWICZ, J.; SHEVCHUK, I. A. Coconvex Pointwise Approximation. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 54, n. 9, p. 1200–1212, 2002. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4159. Acesso em: 5 dec. 2025.