Pebriyanti, Maria, Nur Karomah Dwidayati, and Amidi Amidi. “The Analysis of Students’ Mathematical Connection Ability and Responsibility in Two Stay Two Stray Learning With Problem Cards”. Unnes Journal of Mathematics Education 7, no. 3 (November 30, 2018): 210-217. Accessed September 24, 2020. https://journal.unnes.ac.id/sju/index.php/ujme/article/view/26964.