Gol'dberg, A. A. “Uniqueness Theorems for Algebraic Functions That Take the Number of Algebraic Elements into Account”. Ukrains’kyi Matematychnyi Zhurnal, vol. 47, no. 11, Nov. 1995, pp. 1498–1505, https://umj.imath.kiev.ua/index.php/umj/article/view/5540.