[1]
V. A. Kofanov, “Massiveness of the sets of extremal functions in some problems in approximation theory”, Ukr. Mat. Zhurn., vol. 45, no. 10, pp. 1356–1361, Oct. 1993, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/5940