Noda, Aurelia, and Alicia Bruno. “Assessment of the Knowledge of the Decimal Number System Exhibited by Students With Down Syndrome”. Qualitative Research in Education 6, no. 1 (February 27, 2017): 56–85. Accessed April 28, 2024. https://www.hipatiapress.com/hpjournals/index.php/qre/article/view/2061.