Ryttman, Hans, and K Susanna S Hall-Karlsson. “Brood Size of Twelve Farmland Bird Species in Sweden During 1962—2001”.
Ornis Svecica
19, no. 1 (January 1, 2009): 3–12. Accessed May 30, 2025. https://journals.lub.lu.se/os/article/view/22665.