Widiastuti, Ririn, Kartono Kartono, and Scolastika Mariani. 2021. “Geometry Thinking Ability and Self Efficacy in Problem Based Learning Geogebra Assisted With Self Assessment”. Unnes Journal of Mathematics Education Research 10 (A), 17-29. https://journal.unnes.ac.id/sju/ujmer/article/view/44046.