Ciofi, Carmine, and Graziella Scandurra. “Very Simple and Inexpensive System for Distance Learning With the Use of Chalkboard”. International Journal of Emerging Technologies in Learning (iJET) 16, no. 09 (May 4, 2021): pp. 263–277. Accessed March 29, 2024. https://online-journals.org/index.php/i-jet/article/view/20017.