VelesnitskiiV. F., and SemenchukV. N. “On One Shemetkov Problem”. Ukrains’kyi Matematychnyi Zhurnal 64, no. 9 (September 25, 2012): 1282-1288. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2658.