DK Adult (2005), ISBN 0789477645 Boyle, Steve and Owens, Stephanie (February 6, 2007) North American Beaver (Castor canadensis): A Technical Conservation Assessment.
DK Adult (2005), ISBN 0789477645 Boyle, Steve and Owens, Stephanie (February 6, 2007) North American Beaver (Castor canadensis): A Technical Conservation Assessment.