Fox, Anthony D., Kevin Clausen, Lars Dalby, Thomas Christensen, and Peter Sunde. 2016. “Between-Year Variations in sex/Age Ratio Bias in Hunter Wings of Eurasian Wigeon (Anas Penelope) Compared to Field Samples”. Ornis Fennica 93 (1):26–30. https://doi.org/10.51812/of.133885.