Paulus Nainggolan, Bornok Sinaga. Development of Learning Videos to Improve Students’ Ability to Understand Mathematical Concepts on Polynomial Material. JURRIPEN [Internet]. 2023 Apr. 27 [cited 2024 May 1];2(1):228-39. Available from: https://prin.or.id/index.php/JURRIPEN/article/view/1181