Gaya APA
Effective english programme. (2005).
Jakarta:
Great media.
Gaya Chicago
Effective english programme.
.
Jakarta:
Great media,
2005.
Text.
Gaya MLA
Effective english programme.
.
Jakarta:
Great media,
2005.
Text.
Gaya Turabian
Effective english programme.
Jakarta:
Great media,
2005.
Print.