Ebbinge, Barwolt, Leo van den Bergh, Anton van Haperen, Martin Lok, Jules Philippona, Jan Rooth, and Arend Timmerman. “Numbers and Distribution of Wild Geese in The Netherlands, 1979-1984”. Wildfowl (January 1, 1986): 28–34. Accessed December 16, 2025. https://tidsskrift.dk/Wildfowl/article/view/154784.