Key to North American birds. Containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary, inclusive of Greenland and Lower California, with which are incorporated General ornithology...and Field ornithology. The 5th ed. (entirely rev.) exhibiting the nomenclature of the American ornithologists' union...

Mode of access: Internet.

Key to North American birds. Containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary, inclusive of Greenland and lower California,

Mode of access: Internet.