BOYD, H; OGILVIE, M A. Icelandic Greylag Geese wintering in Britain in 1960-1971. Wildfowl, [S. l.], v. 23, p. 64–82, 1972. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154897. Acesso em: 19 apr. 2026.