Gaya APA

Lougheed, L. ([2010?]). IELTS = International English Language Testing System . Pamulang: Karisma Inti Ilmu.

Gaya MLA

Lougheed, Lin. "IELTS = International English Language Testing System". Pamulang: Karisma Inti Ilmu, [2010?]. Koleksi Elektronik.