Factors Associated with Arrival Densities of Grasshopper Sparrow (Ammodramus Savannarum) and Baird's Sparrow (A. Bairdii) in the Upper Great PlainsDOI: info:10.1525/auk.2009.08154v. 126No. 4American Ornithologists' Union799–808
Ahlering, Marissa A., Johnson, Douglas H., and Faaborg, John. 2009. "Factors Associated with Arrival Densities of Grasshopper Sparrow (Ammodramus Savannarum) and Baird's Sparrow (A. Bairdii) in the Upper Great Plains." The Auk, 126, (4) 799–808. https://doi.org/10.1525/auk.2009.08154.