SARJEANT, W. A. S. Unusual Variations in Plumage of House Sparrow. Blue Jay, [S. l.], v. 47, n. 1, 1989. DOI: 10.29173/bluejay4966. Disponível em: https://bluejayjournal.ca/index.php/bluejay/article/view/4966. Acesso em: 24 jun. 2022.