AbdullayevF. G., BalciS., and Imash kyzy M. “Polynomial Inequalities in Regions With Interior zero angles in the Bergman Space”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 70, no. 3, Mar. 2018, pp. 318-36, http://umj.imath.kiev.ua/index.php/umj/article/view/1559.