Perea Garcia, Juan Olvido, Alessandro Miani, Aage Kristian Olsen Alstrup, Jens Malmkvist, Cino Pertoldi, Trine Hammer Jensen, Rikke Kruse Nielsen, Dan Witzner Hansen, and Lars A. Bach. “Orangulas: Effect of Scheduled Visual Enrichment on Behavioral and Endocrine Aspects of a Captive Orangutan (Pongo pygmaeus): Effect of Scheduled Visual Enrichment on Behavioral and Endocrine Aspects of a Captive Orangutan”. Journal of Zoo and Aquarium Research 8, no. 1 (January 31, 2020): 67–72. Accessed April 29, 2024. https://jzar.org/jzar/article/view/416.