Fox, Anthony D, Bart S Ebbinge, Carl Mitchell, Thomas Heinicke, Tomas Aarvak, Kendrew Colhoun, Preben Clausen, Sergey Dereliev, Sándor Faragó, Kees Koffijberg, Helmut Kruckenberg, Maarten J J E Loonen, Jesper Madsen, Johan Mooij, Petr Musil, Leif Nilsson, Stefan Pihl, and Henk van der Jeugd. “Current Estimates of Goose Population Sizes in Western Europe, a Gap Analysis and an Assessment of Trends”. Ornis Svecica 20, no. 3–4 (October 1, 2010): 115–127. Accessed May 17, 2022. https://journals.lub.lu.se/os/article/view/19922.