Schiffmann, Christian, Linda Schiffmann, Ella Müller, Veronica Cowl, Dennis Müller, and Marcus Clauss. “Solvable Challenges, Meaningful Lives – Welfare and Reproduction in Zoo Animals”. Journal of Zoo and Aquarium Research 13, no. 4 (October 31, 2025): 245–263. Accessed November 1, 2025. https://www.jzar.org/jzar/article/view/902.