Dadashova, I. B., and J. I. Mamedkhanov. “On One Theorem of G. Freud”. Ukrains’kyi Matematychnyi Zhurnal 70, no. 11 (November 25, 2018): 1578-1584. Accessed May 3, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/1662.