Clark, Robert G, Lawson G Sugden, R Kent Brace, and Daniel J Nieman. “The Relationship Between Nesting Chronology and Vulnerability to Hunting of Dabbling Ducks”. Wildfowl 39 (November 1, 1988): 137–144. Accessed April 5, 2026. https://tidsskrift.dk/Wildfowl/article/view/154718.