Παραπομπή σε μορφή APA (7η εκδ.)

Jackie Gaff. (2005). I Wonder Why Pine Trees Have Needles: And Other Questions About Forests. Gardners Books.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Jackie Gaff. I Wonder Why Pine Trees Have Needles: And Other Questions About Forests. Gardners Books, 2005.

Παραπομπή σε μορφή MLA (9th εκδ.)

Jackie Gaff. I Wonder Why Pine Trees Have Needles: And Other Questions About Forests. Gardners Books, 2005.