Identification guide to North American birds, part 1 : Columbidae to Ploceidae : a compendium of information on identifying, ageing, and sexing "near-passerines" and passerines in the hand
· by Peter Pyle; with the collaboration of Steve N.G. Howell, David F. DeSante, Robert P.Yunick, Mary Gustafson; illustrations by Steve N.G. Howell
Bok Engelsk 1997