Gaya APA
Kingsbury, R., Wellman, G.
(1987).
Longman advanced English : coursebook
(
4th ed)
.
Hong Kong:
Longman.
Gaya MLA
Kingsbury, Roy., Wellman, Guy.
"Longman advanced English : coursebook".
4th ed
Hong Kong:
Longman,
1987.
Text.