HudymaU. V. “Best Uniform Approximation of a Continuous Compact-Valued Mapping by Sets of Continuous Single-Valued Mappings”. Ukrains’kyi Matematychnyi Zhurnal 57, no. 12 (December 25, 2005): 1601–1618. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3712.