Cita APA (7th ed.)
West, G. C., & Butler, C. A. (2010). Do hummingbirds hum?: Fascinating answers to questions about hummingbirds. Rutgers University Press.
Cita Chicago (17th ed.)
West, George C., i Carol A. Butler. Do Hummingbirds Hum?: Fascinating Answers to Questions About Hummingbirds. New Brunswick, NJ: Rutgers University Press, 2010.
Cita MLA (9th ed.)
West, George C., i Carol A. Butler. Do Hummingbirds Hum?: Fascinating Answers to Questions About Hummingbirds. Rutgers University Press, 2010.
Atenció: Aquestes cites poden no estar 100% correctes.