Bang, Ha Huy, and Vu Nhat Huy. “Bernstein Inequality for Multivariate Functions With Smooth Fourier Images”. Ukrains’kyi Matematychnyi Zhurnal 74, no. 11 (December 26, 2022): 1558 - 1570. Accessed May 11, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/6386.