Gaya APA

Patrick, H, A, J, C. (1986). Business listening tasks : guide for teacher an self-study . Cambridge: Effendiharahap Publishing Coy.

Gaya MLA

Patrick, Hanks, An, Jim, Corbetl,. "Business listening tasks : guide for teacher an self-study". Cambridge: Effendiharahap Publishing Coy, 1986. Text.