Källander, Hans. “Commensal Use of Mute Swans Cygnus Olor by Common Coot Fulica Atra and of Canada Geese Branta Canadensis by European Wigeon Anas Penelope”. Ornis Svecica 23, no. 2 (April 1, 2013): 108–110. Accessed April 25, 2024. https://journals.lub.lu.se/os/article/view/22580.