Gerstner, K., A. Liesegang, J.-M. Hatt, M. Clauss, and C. Galeffi. “Seasonal Body Mass Changes and Feed Intake in Spectacled Bears (Tremarctos Ornatus) at Zurich Zoo”. Journal of Zoo and Aquarium Research, vol. 4, no. 3, Aug. 2016, pp. 121-6, doi:10.19227/jzar.v4i3.181.