Comparative Analysis of the Closed Quotient for Lip and Tongue Trills in Relation to the Sustained Vowel /ε/ - Cordeiro, Gislaine Ferro; Montagnoli, Arlindo Neto; Nemr, Nair Katia; Menezes, Marcia Helena Moreira; Tsuji, Domingos Hiroshi (Journal of voice, 2012)