Peterson, R. T., & Peterson, V. (1989). A field guide to western birds: A complete new guide to field marks of all speces found in North America west of the 100th meridian & north of Mexico (3rd ed.). Houghton Mifflin.
Chicago Style (17th ed.) CitationPeterson, Roger Tory, and Virginia Peterson. A Field Guide to Western Birds: A Complete New Guide to Field Marks of All Speces Found in North America West of the 100th Meridian & North of Mexico. 3rd ed. New York: Houghton Mifflin, 1989.
MLA (9th ed.) CitationPeterson, Roger Tory, and Virginia Peterson. A Field Guide to Western Birds: A Complete New Guide to Field Marks of All Speces Found in North America West of the 100th Meridian & North of Mexico. 3rd ed. Houghton Mifflin, 1989.
Warning: These citations may not always be 100% accurate.