APA aipamena

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

Chicago Style aipamena

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

MLA aipamena

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

Kontuz: berrikusi erreferentzia hauek erabili aurretik.