Siregar, Saibah, and Mohd Nazran Mohammed Pauzi. “Superordination of Analytic Functions of Koebe Type”. Selangor Science & Technology Review (SeSTeR) 1, no. 2 (July 27, 2018). Accessed January 25, 2022. http://sester.journals.unisel.edu.my/ojs/index.php/sester/article/view/23.