1942 



Erickson, R. C. 1942. Breeding habits of the Canvasback, Nyroca valisineria 

 (Wilson), on the Malheur Wildlife Refuge, Oregon. M.S. thesis, Iowa St. 

 Coll. /Ames , IA. 118 pp. 



1931 



Allen, A. A. 1931. The Canvasback. Bird-Lore 33: 347-360. 



1927 



Beck, H. H. and C. Marburger. 1927. Canvasback in Pennsylvania in summer. 

 Auk 44: 557. 



Canvasback Duck. Photograph by Northern Prairie Wildlife Research Center, 

 U.S. Fish and Wildlife Service. 



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