Gaya APA

Astuti, S, I., Palapah, M, A, O. (2009). Simple Step to TOEFL . Jakarta: HI-FEST PUBLISHING.

Gaya MLA

Astuti, Santi, Indra., Palapah, Maya, Amalia, Oesman. "Simple Step to TOEFL". Jakarta: HI-FEST PUBLISHING, 2009. Text.