Aronsson, Åke. “The Change in Nunbers of Nightjars Caprimulgus Europaeus During Twentyone Years at Ale and Vättle fjäll Near Gothenburg”. Ornis Svecica 5, no. 3–4 (October 1, 1995): 161–164. Accessed May 3, 2024. https://journals.lub.lu.se/os/article/view/23004.