Shchehlov, M. V. “Pointwise Estimation of Sign-Preserving Polynomial Approximation on Arcs in the Complex Plane”. Ukrains’kyi Matematychnyi Zhurnal 74, no. 4 (May 23, 2022): 560 - 568. Accessed March 29, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/7057.