JOHN, R.; PODUVAL, J. D. Voice training for professional voice users. International Journal of Scientific Reports, [S. l.], v. 1, n. 1, p. 65–68, 2015. DOI: 10.18203/issn.2454-2156.IntJSciRep20150204. Disponível em: https://www.sci-rep.com/index.php/scirep/article/view/12. Acesso em: 11 feb. 2025.