Guo, Feng, and Yuha Li. “A New Proof of Bergweiler’s Conjecture Concerning the First Derivative of Transcendental Meromorphic Function With Picard Exceptional Value”. Tamkang Journal of Mathematics 46, no. 1 (March 30, 2015): 91–99. Accessed May 2, 2024. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/1631.