Cita APA (7a ed.)

Martin, B., & Carle, E. (1991). Polar bear, polar bear, what do you hear? H. Holt.

Cita Chicago Style (17a ed.)

Martin, Bill, y Eric Carle. Polar Bear, Polar Bear, What Do You Hear? New York: H. Holt, 1991.

Cita MLA (8a ed.)

Martin, Bill, y Eric Carle. Polar Bear, Polar Bear, What Do You Hear? H. Holt, 1991.