Eissa Saad, M. A. ., and A. M. ElAdl. “Defining and Determining Intellectual Disability (Intellectual Developmental Disorder): Insights from DSM-5”. Psycho-Educational Research Reviews, vol. 8, no. 1, Apr. 2019, pp. 51-54, https://perrjournal.com/index.php/perrjournal/article/view/192.