Estilo APA
Widjaja, G. (2007).
Certain Important English Conversation .
Upper Saddle River, NJ:
PT. Bhuana Ilmu Populer.
Estilo MLA
Widjaja, Grace.
"Certain Important English Conversation".
Upper Saddle River, NJ:
PT. Bhuana Ilmu Populer,
2007.
Text.