Spaans , Bernard, Martin Stock, Andrew St. Joseph, Hans-Heiner Bergmann, and Barwolt S. Ebbinge. 1993. “Breeding Biology of Dark-Bellied Brent Geese Branta B. Bernicla in Taimyr in 1990 in the Absence of Arctic Foxes and under Favourable Weather Conditions”. Polar Research 12 (2):117-30. https://doi.org/10.3402/polar.v12i2.6708.