Amani, M., R. Asadi Gandomani, and A. Nesayan. “A Study of Academic Factors Underlying First Grade Retention in Primary Schools of North Khorasan”. International Electronic Journal of Elementary Education, vol. 12, no. 4, Apr. 2020, pp. 325-33, https://iejee.com/index.php/IEJEE/article/view/998.