Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

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

Cita MLA (8a ed.)

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