Gaya APA

Postill, S., Sudrajat, H. (2007). Travel by air : English for special purpose conversational approach (cet. ke-7). Jakarta: Kesaint Blanc.

Gaya MLA

Postill, Sara-Jane., Sudrajat, Herman. "Travel by air : English for special purpose conversational approach". cet. ke-7 Jakarta: Kesaint Blanc, 2007. Text.