Gaya APA

Yenni, W, E, P, &. (2018). BUKU PINTAR IELTS : International English Language Testing System (edisi 2). YOGYAKARTA: B FIRST.

Gaya MLA

Yenni, Wendratama, Engelbertus,, Purwaningsih, &. "BUKU PINTAR IELTS : International English Language Testing System". edisi 2 YOGYAKARTA: B FIRST, 2018. Text.