Viain, Anouck, Frédéric Corre, Philippe Delaporte, Emmanuel Joyeux, and Pierrick Bocher. 2013. “Numbers, Diet and Feeding Methods of Common Shelduck Tadorna Tadorna Wintering in the Estuarine Bays of Aiguillon and Marennes-Ol”. Wildfowl, April, 121-41. https://tidsskrift.dk/Wildfowl/article/view/153547.