Dovgoshei, A. A., and L. L. Potemkina. “Analyticity of Higher-Order Moduli of Continuity of Real-Analytic Functions”. Ukrains’kyi Matematychnyi Zhurnal 55, no. 6 (June 25, 2003): 750-761. Accessed May 10, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3950.