FRØKJÆR-JENSEN, B. Comparisons between the Vowel Formant Frequencies in Speech and Song. Annual Report of the Institute of Phonetics University of Copenhagen, [S. l.], v. 3, p. 115–127, 1969. DOI: 10.7146/aripuc.v3i.130757. Disponível em: https://tidsskrift.dk/ARIPUC/article/view/130757. Acesso em: 3 may. 2024.