SMALLWOOD, M. Vocal difficulties for mid-career classical singers: A preliminary quantitative analysis. Young Scientific Music and Dance Forum : Conference with international participation, [S. l.], n. 15, p. 147–155, 2022. Disponível em: https://ojs.nbu.bg/index.php/YSMDF/article/view/614. Acesso em: 26 apr. 2024.