KOTRSCHAL, Kurt; HEMETSBERGER, Josef; DITTAMI, John. Vigilance in a flock of semi-tame Greylag Geese Answer answer in response to approaching eagles Haliaeetus albicilla and Aquila chrysaetos. Wildfowl, [S. l.], p. 215–219, 1992. Disponível em: https://tidsskrift.dk/Wildfowl/article/view/155354. Acesso em: 17 dec. 2025.