PICHUGOV, S. A. Inverse Jackson theorems in spaces with integral metric. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 64, n. 3, p. 351–362, 2012. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2581. Acesso em: 5 dec. 2025.