Kotsur, I. M., and M. F. Kotsur. “On the Radii of Convexity and Starlikeness for Some Special Classes of Analytic Functions in a Disk”. Ukrains’kyi Matematychnyi Zhurnal 48, no. 7 (July 25, 1996): 954–958. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/5268.