BLACK, Jeffrey M; SALMON, David G; BELL, Mike. Distribution of Whooper Swans Cygnus cygnus in Britain and Ireland in relation to habitat type and flock social structure. Wildfowl, [S. l.], p. 278, 2013. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154963. Acesso em: 17 dec. 2025.