Leppik, Katrin, and Cristian Tejedor-García. “Estoñol, a Computer-Assisted Pronunciation Training Tool for Spanish L1 Speakers to Improve the Pronunciation and Perception of Estonian Vowels”. Eesti ja soome-ugri keeleteaduse ajakiri. Journal of Estonian and Finno-Ugric Linguistics 10, no. 1 (December 17, 2019): 89–104. Accessed March 29, 2024. https://ojs.utlib.ee/index.php/jeful/article/view/jeful.2019.10.1.05.