Kopotun, K.A. and Listopad, V.V. (1994) “On monotone and convex approximation by algebraic polynomials”,
Ukrains’kyi Matematychnyi Zhurnal, 46(9), pp. 1266–1270. Available at:
https://umj.imath.kiev.ua/index.php/umj/article/view/5644 (Accessed: 10 April 2025).