DIRKSEN, Sjoerd; BEEKMAN, Jan H; SLAGBOOM, Teus H. Bewick’s Swans Cygnus columbianus bewickii in the Netherlands: numbers, distribution and food choice during the wintering season. Wildfowl, [S. l.], p. 228–237, 2013. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154973. Acesso em: 17 dec. 2025.