Gaya APA

Beaumont, J. (2006). Northstar: Building Skills for the TOEFL Ibt, Intermediate Student Book . New York: Pearson Education, Inc..

Gaya MLA

Beaumont, John. "Northstar: Building Skills for the TOEFL Ibt, Intermediate Student Book". New York: Pearson Education, Inc., 2006. Buku.