NIVEN, William. The Land, The Birds, Through 50 Years in Aspen Parkland. Blue Jay, [S. l.], v. 31, n. 4, 1970. DOI: 10.29173/bluejay3801. Disponível em: https://bluejayjournal.ca/index.php/bluejay/article/view/3801. Acesso em: 30 apr. 2024.