Bengtsson, Daniel, and Niclas Jonzén. “Autumn Migration of Montagu’s Harrier Circus Pygargus and Marsh Harrier C. Aeruginosus at the Southern Tip of Öland”. Ornis Svecica 11, no. 1–2 (April 1, 2001): 1–6. Accessed April 24, 2024. https://journals.lub.lu.se/os/article/view/22857.