AGOSHKOVA, T. A. Approximation of Periodic Functions of Many Variables in Metric Spaces by Piecewise-Constant Functions. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 65, n. 10, p. 1303–1314, 2013. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2510. Acesso em: 5 dec. 2025.