Boiko, D. and Kampe-Persson, H. (2013) “Breeding Whooper Swans Cygnus cygnus in Latvia, 1973-2009”, Wildfowl, 60, pp. 168–177. Available at: https://tidsskrift.dk/Wildfowl/article/view/153535 (Accessed: 15 April 2026).