E. Núñez Barriopedro and R. Ravina Ripoll, “Measure of the utility of the digital resources for learning languages”, Teor. Enfoques. Apl. Cienc. Soc., vol. 10, no. 21, pp. 39–48, Dec. 2017, Accessed: Oct. 05, 2026. Available: https://mail.revistas.uclave.org/index.php/teacs/article/view/1448