APA (7th ed.) Citation

Peterson, R. T. (1941). A field guide to western birds. Houghton Mifflin company.

Chicago Style (17th ed.) Citation

Peterson, Roger Tory. A Field Guide to Western Birds. Boston: Houghton Mifflin company, 1941.

MLA (9th ed.) Citation

Peterson, Roger Tory. A Field Guide to Western Birds. Houghton Mifflin company, 1941.