HASHMI, A.; SULLIVAN, M. The visitor effect in zoo-housed apes: the variable effect on behaviour of visitor number and noise. Journal of Zoo and Aquarium Research, [S. l.], v. 8, n. 4, p. 268–282, 2020. DOI: 10.19227/jzar.v8i4.523. Disponível em: https://jzar.org/jzar/article/view/523. Acesso em: 4 dec. 2020.