BabenkoV. F., and PichugovS. A. “On Kolmogorov-Type Inequalities for Fractional Derivatives of Functions of Two Variables”. Ukrains’kyi Matematychnyi Zhurnal 60, no. 6 (June 25, 2008): 837–842. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3200.