Zamorano Urrutia, F. J., Cortés Loyola, C. and Herrera Marín, M. (2019) “A Tangible User Interface to Facilitate Learning of Trigonometry”, International Journal of Emerging Technologies in Learning (iJET), 14(23), pp. pp. 152–164. doi: 10.3991/ijet.v14i23.11433.