Gaya APA

, T, F, (., (Pengarang), , K, S. (2009). NorthStar 4 : Listening and Speaking (4). United States of America :: PEARSON EDUCATION,.

Gaya MLA

, Tess, Ferree, (Pengarang)., (Pengarang), , Kim, Sanabria. "NorthStar 4 : Listening and Speaking". 4 United States of America :: PEARSON EDUCATION,, 2009. Monograf.