DALE, Svein. Density, numbers and origin of Northern Hawk Owls Surnia ulula in southern Norway during the 2016 irruption. Ornis Norvegica, [S. l.], v. 40, p. 1–13, 2017. DOI: 10.15845/on.v40i0.1079. Disponível em: https://boap.uib.no/index.php/ornis/article/view/1079. Acesso em: 22 dec. 2024.