HEMBARS’KA, S. B.; ZADEREI , P. V. Best orthogonal trigonometric approximations of the Nikol’skii – Besov-type classes of periodic functions in the space $B_{\infty,1}$. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 74, n. 6, p. 772–783, 2022. DOI: 10.37863/umzh.v74i6.7070. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/7070. Acesso em: 5 dec. 2025.