Gaya APA
Written english for business. (1990).
Hongkong:
Oxford University Press.
Gaya Chicago
Written english for business.
.
Hongkong:
Oxford University Press,
1990.
Text.
Gaya MLA
Written english for business.
.
Hongkong:
Oxford University Press,
1990.
Text.
Gaya Turabian
Written english for business.
Hongkong:
Oxford University Press,
1990.
Print.