Amidi, Amidi, and Farah Zahra. “The Students’ Activity Profiles and Mathematic Problem Solving Ability on the LAPS-Heuristic Model Learning”. Unnes Journal of Mathematics Education 7, no. 1 (March 29, 2018): 72-77. Accessed October 26, 2020. https://journal.unnes.ac.id/sju/index.php/ujme/article/view/17087.