Cita APA (7th ed.)

Willems, M. (2011). Happy Pig Day! Hyperion Books for Children.

Cita Chicago (17th ed.)

Willems, Mo. Happy Pig Day! New York: Hyperion Books for Children, 2011.

Cita MLA (8th ed.)

Willems, Mo. Happy Pig Day! Hyperion Books for Children, 2011.