U.S. Fish and Wildlife Service (January 15, 2008). "All About the Peregrine Falcon". Department of the Interior. Archived from the original on 2008-04-16. Retrieved 14 May 2013.
Kirschbaum, Kari; Ivory, Alicia (2002). "Aquila chrysaetos golden eagle". The Animal Diversity Web. University of Michigan Museum of Zoology. Retrieved 14 May 2013.
web.archive.org
U.S. Fish and Wildlife Service (January 15, 2008). "All About the Peregrine Falcon". Department of the Interior. Archived from the original on 2008-04-16. Retrieved 14 May 2013.