1.
Romanyuk AS. The best trigonometric and bilinear approximations for functions of many variables from the classes $B^r_{p, \theta}$. II. Ukr. Mat. Zhurn. [Internet]. 1993Oct.25 [cited 2024Sep.1];45(10):1411–1423. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/5946