Cesaro means of negative order of the quadratic partial sums of double Vilenkin-Fourier series. Nonlinear Studies, [S. l.], v. 29, n. 1, 2022. Disponível em: https://www.nonlinearstudies.com/index.php/nonlinear/article/view/2815. Acesso em: 18 sep. 2025.