Babenko, V., et al. “Some Sharp Landau-Kolmogorov–Nagy-Type Inequalities in Sobolev Spaces of Multivariate Functions”. Ukrains’kyi Matematychnyi Zhurnal, vol. 75, no. 10, Oct. 2023, pp. 1347-53, https://doi.org/10.3842/umzh.v75i10.7680.