RITVO, S. E.; MACDONALD, S. E. Music as enrichment for Sumatran orangutans (Pongo abelii). Journal of Zoo and Aquarium Research, [S. l.], v. 4, n. 3, p. 156–163, 2016. DOI: 10.19227/jzar.v4i3.231. Disponível em: https://jzar.org/jzar/article/view/231. Acesso em: 19 jan. 2022.