GOGINAVA, U. Strong summability of two-dimensional Vilenkin – Fourier series. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 71, n. 3, p. 340–352, 2019. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1443. Acesso em: 5 dec. 2025.