HUTTERS, B.; HOLTSE, P. On Universals in Vowel Perception. Annual Report of the Institute of Phonetics University of Copenhagen, [S. l.], v. 6, p. 177–184, 1972. DOI: 10.7146/aripuc.v6i.130911. Disponível em: https://tidsskrift.dk/ARIPUC/article/view/130911. Acesso em: 4 may. 2024.