Boiko, Dmitrijs, and Hakon Kampe-Persson. “Winter Distribution of Whooper Swans Cygnus Cygnus Cygnets Bred in Latvia, 2004-2008”. Wildfowl (April 16, 2013): 74–89. Accessed December 16, 2025. https://tidsskrift.dk/Wildfowl/article/view/153549.