Voloshyn, H.A., and V.K. Maslyuchenko. “On Approximation of the Separately Continuous Functions $2\pi$-Periodical in Relation to the Second Variable”. Carpathian Mathematical Publications 2, no. 1 (June 30, 2010): 4–14. Accessed November 22, 2024. https://ktipe.pnu.edu.ua/index.php/cmp/article/view/3975.