Zuhairi, Aminudin. “THE OPERATIONAL ASPECTS OF OPEN AND DISTANCE LEARNING AND ITS QUALITY ASSURANCE SYSTEM IN UNIVERSITAS TERBUKA”. Jurnal Pendidikan Terbuka Dan Jarak Jauh 20, no. 2 (January 30, 2020): 74-89. Accessed July 28, 2021. https://jurnal.ut.ac.id/index.php/jptjj/article/view/122.