Muhamad Sabirin, S. . Aminah, Muhniansyah, and Muh. Fajaruddin Atsnan. “Students’ Skills Performing Mathematical Reasoning and Communication through Group Investigation Learning Model”. Jurnal Pengembangan Pembelajaran Matematika, vol. 3, no. 2, Aug. 2021, pp. 112-28, doi:10.14421/jppm.2021.32.112-128.