Sari, Puspita, Mimi Nur Hajizah, and Swida Purwanto. 2020. “The Neutralization on an Empty Number Line Model for Integer Additions and Subtractions: Is It Helpful?”. Journal on Mathematics Education 11 (1):1-16. http://jme.ejournal.unsri.ac.id/index.php/jme/article/view/3677.