TERTERYAN, A.A. Positive difference operators of any preassigned approximation order for the second derivative. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 11, p. 1590–1597, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8262. Acesso em: 17 apr. 2025.