Gaya APA
english for academic purpose essay writing. (2007).
Yogyakarta:
Andi.
Gaya Chicago
english for academic purpose essay writing.
.
Yogyakarta:
Andi,
2007.
Buku.
Gaya MLA
english for academic purpose essay writing.
.
Yogyakarta:
Andi,
2007.
Buku.
Gaya Turabian
english for academic purpose essay writing.
Yogyakarta:
Andi,
2007.
Buku.