Patrick J. Weatherhead, KATHERINE E. MUMA, J. Dylan Maddox, Jenny M. Knox, and Kevin W. Dufour. 2007. "Morphology Versus Molecules: Sexing Red-winged Blackbird Nestlings." J Field Ornithol. 78(4):428-435.
View the PDF of the abstract at https://www.ithaca.edu/biology/article_muma07.pdf
https://www.ithaca.edu/intercom/article.php/20071211140706350