LAUBEK, Bjarke et al. Whooper Swan Cygnus cygnus January population censuses for Northwest Mainland Europe, 1995–2015. Wildfowl, [S. l.], p. 103–122, 2019. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154490. Acesso em: 16 dec. 2025.