Hedenström, Anders, Åke Lindström, and Jan Pettersson. “Interrupted Moult of Adult Willow Warblers Phylloscopus Trochilus During Autumn Migration through Sweden”. Ornis Svecica 5, no. 2 (April 1, 1995): 69–74. Accessed March 28, 2024. https://journals.lub.lu.se/os/article/view/23006.