Ammon, Elisabeth M., and William M. Gilbert. 1999. “Wilson's Warbler (Cardellina pusilla).” The Birds of North America, edited by Paul G. Rodewald. Ithaca: Cornell Lab of Ornithology. Retrieved from the Birds of North America: https://birdsna.org/Species-Account/bna/species/wlswar doi: 10.2173/bna.478