FEDUNYK-YAREMCHUK, O.V.; HEMBARS’KA, S.B. Best orthogonal trigonometric approximations of the Nikol’skii-Besov-type classes of periodic functions of one and several variables. Carpathian Mathematical Publications, [S. l.], v. 14, n. 1, p. 171–184, 2022. DOI: 10.15330/cmp.14.1.171-184. Disponível em: https://journals.pnu.edu.ua/index.php/cmp/article/view/5928. Acesso em: 4 may. 2024.