Gaya APA

Postil, S. (1997). Travel by air: English For Special Purpose ( ESP) Coversational Approch (c-2). Jakarta: Visipro.

Gaya MLA

Postil, Sara-Jane. "Travel by air: English For Special Purpose ( ESP) Coversational Approch". c-2 Jakarta: Visipro, 1997. 400_Language.