WASET
d’Apolito, I. , Sisinni, B. , Grimaldi, M. , Fivela, B. (2017), 'Perceptual and Ultrasound Articulatory Training Effects on English L2 Vowels Production by Italian Learners ', World Academy of Science, Engineering and Technology, Open Science Index 128, International Journal of Cognitive and Language Sciences, 11(8), 2174 - 2181.