STASYUK, S. A. Best $m$-term approximation of the classes $B ^{r}_{\infty, \theta}$ of functions of many variables by polynomials in the haar system. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 63, n. 4, p. 549–555, 2011. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2740. Acesso em: 5 dec. 2025.