Gaya APA

Lougheed, L., Agustina, T, S. (2016). Barrons Ielts Integrational English Language Testing System (4th Edition). New York: Barrons Educational Series.

Gaya MLA

Lougheed, Lin., Agustina, Tri, Siwi. "Barrons Ielts Integrational English Language Testing System". 4th Edition New York: Barrons Educational Series, 2016. Text.