Persson L-E, Tephnadze G, Tutberidze G, Wall P. Some new resuts concering strong convergence of Fejér means with respect to Vilenkin systems. Ukr. Mat. Zhurn. [Internet]. 2021 Apr. 21 [cited 2025 Apr. 13];73(4):544-55. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/226