TEPHNADZE, G. Strong Convergence of Two-Dimensional Walsh–Fourier Series. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 65, n. 6, p. 822–834, 2013. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2467. Acesso em: 5 dec. 2025.