Anderson, Helen, Christiaane Hübner, James Speed, Jesper Madsen, and René van der Wal. “Biding Time before Breeding: Flexible Use of the Arctic Landscape by Migratory Geese During Spring”. Polar Research 340 (July 7, 2015). Accessed October 18, 2019. https://polarresearch.net/index.php/polar/article/view/3232.