Beyersbergen, Gerard W., Neal D. Niemuth, and Michael R. Norton. 2004. Northern Prairie and Parkland Waterbird Conservation Plan, A Plan Associated with the Waterbird Conservation for the Americas Initiative. Denver, CO: Prairie Pothole Joint Venture. https://www.fws.gov/mountain-prairie/refuges/hapetResources/updatedFiles/publications/Beyersbergen.et.al.2004.waterbird.plan.PPJV.pdf