Ruth Mayasari Simanjuntak, and Adi Suarman Situmorang. “THE EFFECT OF PROBLEM POSING LEARNING MODEL ON STUDENT’S MATHEMATIC REASONING ABILITY”. European Journal of Humanities and Educational Advancements, vol. 2, no. 8, Aug. 2021, pp. 11-14, https://scholarzest.com/index.php/ejhea/article/view/1123.