CURRY, E.; SAFAYI, S.; MEYERSON, R.; ROTH, T. Reproductive trends of captive polar bears in North American zoos: a historical analysis. Journal of Zoo and Aquarium Research, [S. l.], v. 3, n. 3, p. 99–106, 2015. DOI: 10.19227/jzar.v3i3.133. Disponível em: https://jzar.org/jzar/article/view/133. Acesso em: 26 oct. 2021.