Gaya APA

Training, I, O, E, L. et al (2013). Buku Pintar IELTS (International English Language Testing System) . Yogyakarta: B first.

Gaya MLA

Training, Institute, Of, English, Language. et al. "Buku Pintar IELTS (International English Language Testing System)". Yogyakarta: B first, 2013. Book.