DALE, S. Breeding population increase and range expansion of the Whooper Swan Cygnus cygnus in Oslo and Akershus. Ornis Norvegica, [S. l.], v. 39, p. 29–36, 2016. DOI: 10.15845/on.v39i0.1032. Disponível em: https://boap.uib.no/index.php/ornis/article/view/1032. Acesso em: 24 apr. 2024.