Lindström, Åke, Staffan Bensch, and Anders Hedenström. “An Exceptionally Large Willow Warbler Phylloscopus Trochilus”. Ornis Svecica 22, no. 3–4 (October 1, 2012): 139–141. Accessed April 26, 2024. https://journals.lub.lu.se/os/article/view/22590.