Fatmasari, H., S. Waluya, and S. Sugianto. “Mathematical Problem Solving Ability Viewed from Self-Efficacy of 7th Grade Students”. Unnes Journal of Mathematics Education Research, Vol. 10, no. A, Dec. 2020, pp. 206-11, https://journal.unnes.ac.id/sju/ujmer/article/view/43208.