APA Style
Doff, A. et al (2016).
Cambridge English Empower Starter Student's Book w/OL Assessment & OL WB .
Cambridge:
Cambride University PRESS.
MLA Style
Doff, Adrian. et al.
"Cambridge English Empower Starter Student's Book w/OL Assessment & OL WB".
Cambridge:
Cambride University PRESS,
2016.
Bahasa Inggris.