BabenkoV. F., and PichugovS. A. “Approximation of Continuous Vector Functions”. Ukrains’kyi Matematychnyi Zhurnal 46, no. 11 (November 25, 1994): 1435–1448. Accessed October 6, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5583.