Hinrichs, Simon, Jean-Louis Berthoud, and Friederike Woog. “Urban Greylag Geese Anser Anser Nesting on Roofs in the City of Hamburg, Northern Germany”. Wildfowl 75 (December 12, 2025). Accessed February 4, 2026. https://tidsskrift.dk/Wildfowl/article/view/162737.