Zulfa, A., K. Kartono, and A. Nur Cahyono. “Mathematical Communication Skills in Terms of Self Efficacy Through Guided Discovery Learning Assisted Immediate Feedback”. Unnes Journal of Mathematics Education Research, Vol. 10, no. A, Jan. 2021, pp. 75-82, http://journal.unnes.ac.id/sju/ujmer/article/view/34665.