Fadillah, L., K. Kartono, and S. Supriyadi. “Mathematical Communication Ability Based On Cognitive Style in PBL With Tutor Feedback Assisted by Triangle Calculator”. Unnes Journal of Mathematics Education Research, Vol. 9, no. 1, June 2020, pp. 86-92, https://journal.unnes.ac.id/sju/ujmer/article/view/32196.