Rahmawati, Desy. “IMPLEMENTASI GROUP INVESTIGATION DENGAN SCIENTIFIC APPROACH BERBASIS PORTOFOLIO TERHADAP KEMAMPUAN BERPIKIR KRITIS MATEMATIS”. Unnes Journal of Mathematics Education 3, no. 3 (November 23, 2014). Accessed May 4, 2024. http://journal.unnes.ac.id/sju/ujme/article/view/4488.