Simonyan, L.S. “ON CONVERGENCE OF THE FOURIER DOUBLE SERIES WITH RESPECT TO THE VILENKIN SYSTEMS”. Proceedings of the YSU A: Physical and Mathematical Sciences 52, no. 1 (245) (April 16, 2018): 12–18. Accessed May 19, 2024. https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol52_no1_2018_pp012-018.