BOYD, H; OGILVIE, M A. Icelandic Greylag Geese wintering in Britain in 1960-1971. Wildfowl, [S. l.], p. 64–82, 1972. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/154897. Acesso em: 17 dec. 2025.