Dahl, F. M. ., Hanse, H. H. ., Vorup, L. D. ., Jensen, L. Østergaard ., Spyridopoulos, P. S. ., Jensen, T. H. ., Pertoldi, C. ., Alstrup, A. K. O. ., & Pagh, S. . (2020). Effect of enrichments on behavioural reaction norms of two captive polar bears (Ursus maritimus) in Aalborg Zoo, Denmark. Genetics & Biodiversity Journal, 4(2), 61–72. https://doi.org/10.46325/gabj.v4i2.98