APA (7th ed.) Citation

American Ornithologists' Union. (1931). Check-list of North American birds (4th ed.). The Union.

Chicago Style (17th ed.) Citation

American Ornithologists' Union. Check-list of North American Birds. 4th ed. Lancaster, Pa.: The Union, 1931.

MLA (9th ed.) Citation

American Ornithologists' Union. Check-list of North American Birds. 4th ed. The Union, 1931.

Warning: These citations may not always be 100% accurate.