Kadir, Abdul, Rochmad Rochmad, and Iwan Junaedi. “Mathematical Connection Ability of Grade 8th Students’ in Terms of Self-Concept in Problem Based Learning”. Journal of Primary Education 9, no. 3 (May 31, 2020): 258-266. Accessed September 21, 2020. https://journal.unnes.ac.id/sju/index.php/jpe/article/view/37547.