Gaya APA
HOPKINS, D., CULLEN, P. (2007).
CAMBRIDGE ENGLISH GRAMMAR FOR IELTS .
JAKARTA BARAT:
CAMBRIDGE UNIVERSITY PRESS.
Gaya MLA
HOPKINS, DIANA., CULLEN, PAULINE.
"CAMBRIDGE ENGLISH GRAMMAR FOR IELTS".
JAKARTA BARAT:
CAMBRIDGE UNIVERSITY PRESS,
2007.
Text.