DORONIN, V. G.; LIGUN, A. A. Exact constants in inequalities of the jackson type for quadrature formulas. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 52, n. 1, p. 46–51, 2000. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4395. Acesso em: 5 dec. 2025.