Follestad, Arne, Torgeir NygÃ¥rd, Nils Røv, and Bjørn Harald Larsen. 1988. “Distribution and Numbers of Moulting Non-Breeding Greylag Geese in Norway”. Wildfowl, January, 82-87. https://tidsskrift.dk/Wildfowl/article/view/154719.