Cita APA (7th ed.)

Amy Shields. (2011). National Geographic Readers: Trains. National Geographic Children's Books.

Cita Chicago (17th ed.)

Amy Shields. National Geographic Readers: Trains. National Geographic Children's Books, 2011.

Cita MLA (9th ed.)

Amy Shields. National Geographic Readers: Trains. National Geographic Children's Books, 2011.

Atenció: Aquestes cites poden no estar 100% correctes.