Friedl, Markus, Markus Ebner, and Martin Ebner. “Mobile Learning Applications for Android Und IOS for German Language Acquisition Based on Learning Analytics Measurements”. International Journal of Learning Analytics and Artificial Intelligence for Education (iJAI) 2, no. 1 (March 3, 2020): pp. 4–13. Accessed January 28, 2023. https://online-journals.org/index.php/i-jai/article/view/12317.