Avisca KCW, Mawardi M, Astuti S. RETRACTION: Peningkatan Critical Thinking dan Collaborative Skill Matematika melalui Model Group Investigation Berbantuan Magic Ball. JP [Internet]. 2018 Nov. 16 [cited 2025 Mar. 15];3(2):97-103. Available from: https://journal.unesa.ac.id/index.php/jp/article/view/2280