APA (7th ed.) Citation

Marx, H., & Barber, R. Harpo speaks!

Chicago Style (17th ed.) Citation

Marx, Harpo, and Rowland Barber. Harpo Speaks!

MLA (9th ed.) Citation

Marx, Harpo, and Rowland Barber. Harpo Speaks!

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