On monotone and convex approximation by algebraic polynomials

Kopotun, K. A., and V. V. Listopad. “On Monotone and Convex Approximation by Algebraic Polynomials”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 46, no. 9, Sept. 1994, pp. 1266–1270, https://umj.imath.kiev.ua/index.php/umj/article/view/5644.