Heldbjerg, Henning, and Lennart Karlsson. “Autumn Migration of Blue Tit Parus Caeruleus at Falsterbo, Sweden 1980–94: Population Changes, Migration Patterns and Recovery Analysis”. Ornis Svecica 7, no. 3–4 (October 1, 1997): 149–167. Accessed May 11, 2024. https://journals.lub.lu.se/os/article/view/22968.