Cita APA (7a ed.)

Mayer, M. (2008). It's Earth Day! HarperFestival.

Cita Chicago Style (17a ed.)

Mayer, Mercer. It's Earth Day! New York: HarperFestival, 2008.

Cita MLA (8a ed.)

Mayer, Mercer. It's Earth Day! HarperFestival, 2008.