Horiguchi, Tomoya, Takahito Tomoto, and Tsukasa Hirashima. “A Framework of Generating Explanation for Conceptual Understanding Based on ‘semantics of constraints’”. Research and Practice in Technology Enhanced Learning 10 (June 23, 2015). Accessed May 2, 2024. https://rptel.apsce.net/index.php/RPTEL/article/view/2015-10002.