Gaya APA

Hidayati, N, N., Rizka, H. (2015). IELTS Preparation . Yogyakarta: Pustaka Baru Press.

Gaya MLA

Hidayati, Niswatin, Nurul., Rizka, Haira. "IELTS Preparation". Yogyakarta: Pustaka Baru Press, 2015. Teks.