Agoshkova TA. Approximation of Periodic Functions of Many Variables in Metric Spaces by Piecewise-Constant Functions. Ukr. Mat. Zhurn. [Internet]. 2013Oct.25 [cited 2024Dec.4];65(10):1303–1314. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/2510