DEGERNES, L A; FRANK, R K. Causes of mortality in Trumpeter Swans Cygnus buccinator in Minnesota 1986-89. Wildfowl, [S. l.], p. 352–355, 2013. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154953. Acesso em: 17 dec. 2025.