Babenko, V. F., and M. S. Churilova. “Comparison of Exact Constants in Kolmogorov-Type Inequalities for Periodic and Nonperiodic Functions of Many Variables”. Ukrains’kyi Matematychnyi Zhurnal 58, no. 5 (May 25, 2006): 597–606. Accessed May 1, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3478.