Avisca, K. C. W., Mawardi, M. and Astuti, S. (2018) “RETRACTION: Peningkatan Critical Thinking dan Collaborative Skill Matematika melalui Model Group Investigation Berbantuan Magic Ball”, JP (Jurnal Pendidikan) : Teori dan Praktik, 3(2), pp. 97–103. doi: 10.26740/jp.v3n2.p97-103.