APA-ийн эшлэл(7 дахь хэвлэлт)

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

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

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

MLA -ийн эшлэл (9 дэх хэвлэлт)

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