Clausen, P. (2020).
Branta bernicla - Brent Goose. I V. Keller, S. Herrando, P. Vorisek, M. Franch, M. Kipson, P. Milanesi, D. Marti, M. Anton, A. Klvanova, M. V. Kalyakin, H.-G. Bauer & R. P. B. Foppen (red.),
European Breeding Bird Atlas 2: Distribution, Abundance and Change (s. 110). European Bird Census Council & Lynx Edicions.