ROMANYUK, V. S. Multiple Haar basis and $m$-term approximations of functions from the Besov classes. II. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 68, n. 6, p. 816–825, 2016. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1880. Acesso em: 14 apr. 2025.