GUDRA, Tadeusz; OPIELIŃSKI, K.J.; SOBCZAK, T. Ultrasonic examination of the tongue shape changes in the process of articulation of vowels. Archives of Acoustics, [S. l.], v. 31, n. 4(S), p. 9–16, 2014. Disponível em: https://acoustics3.ippt.pan.pl/index.php/aa/article/view/1316. Acesso em: 26 apr. 2025.