gozim, Mohamed, and Djamila Hermez. “the Effectiveness of the Differentiated Education Strategy in Teaching Mathematical Concepts to Educationally Retarded Pupilsin the First-Grade School ”. Al-Jamie Journal In Psychological Studies and Educational Sciences, vol. 6, no. 1, Apr. 2021, pp. 353-72, https://journals.univ-msila.dz/index.php/ajpe/article/view/9461.