“Bilinear Approximations of the Classes $S^{\Omega}_{p,{\theta}}B$ of Periodic Functions of Many Variables”. Transactions of Institute of Mathematics, the NAS of Ukraine 14, no. 3 (November 28, 2017): 332–353. Accessed September 11, 2026. https://trim.imath.kiev.ua/index.php/trim/article/view/326.