DunduchenkoL. E. “On Non-Emptiness of One Class of Functions Analytical in a Finite-Connected Circular Domain ”. Ukrains’kyi Matematychnyi Zhurnal 23, no. 4 (June 29, 1971): 454-463. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/8579.