Gaya APA

Amrullah, A., Sikumbang, R. (2018). English for university students (Cet. 1). Bogor: Ghalia Indonesia.

Gaya MLA

Amrullah, Amiruddin., Sikumbang, Risman. "English for university students". Cet. 1 Bogor: Ghalia Indonesia, 2018. Text.