Worden, J. (2013) “Numbers and distribution of Bewick’s Swan Cygnus columbianus bewickii wintering in Britain and Ireland: results of international censuses, January 1995, 2000 and 2005”, Wildfowl, pp. 3–22. Available at: https://tidsskrift.dk/Wildfowl/article/view/153969 (Accessed: 17 December 2025).