Berg, Åke, and Olle Kvarnbäck. “Density and Reproductive Success of Skylarks Alauda Arvensis on Organic farms—an Experiment With Unsown Skylark Plots on Autumn Sown Cereals”. Ornis Svecica 21, no. 1 (January 1, 2011): 3–10. Accessed April 15, 2024. https://journals.lub.lu.se/os/article/view/22613.