PARFINOVYCH, N. V. Exact order of relative widths of classes $W^r_1$ in the space $L_1$. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 57, n. 10, p. 1409–1417, 2005. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3694. Acesso em: 6 dec. 2025.