TerteryanA.A. “Positive Difference Operators of Any Preassigned Approximation Order for the Second Derivative”. Ukrains’kyi Matematychnyi Zhurnal 44, no. 11 (November 6, 1992): 1590-1597. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/8262.