Heins, Maurice. “A Property of the Asymptotic Spots of a Meromorphic Function or an Interior Transformation Whose Domain Is the Open Unit Disk”. The Journal of the Indian Mathematical Society 24, no. 1-2 (June 1, 1960): 265–268. Accessed May 8, 2024. https://www.informaticsjournals.com/index.php/jims/article/view/16911.