Παραπομπή σε μορφή APA (7η εκδ.)

Ferree, T., & Sanabria, K. (1998). NorthStar: Focus on listening and speaking, high intermediate. Longman.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Ferree, Tess, και Kim Sanabria. NorthStar: Focus on Listening and Speaking, High Intermediate. Nueva York: Longman, 1998.

Παραπομπή σε μορφή MLA (9th εκδ.)

Ferree, Tess, και Kim Sanabria. NorthStar: Focus on Listening and Speaking, High Intermediate. Longman, 1998.