SEMENYUK, V. B. Approximation of differentiable functions by polynomial splines in domains with external peaks. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 46, n. 9, p. 1224–1233, 1994. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5639. Acesso em: 5 dec. 2025.