Bakhtin, A. K. “A Problem of Extreme Decomposition of the Complex Plane With Free Poles”. Ukrains’kyi Matematychnyi Zhurnal 71, no. 10 (October 25, 2019): 1299-1320. Accessed October 2, 2022. http://umj.imath.kiev.ua/index.php/umj/article/view/1516.