Gaya APA
Pitman business english 1. (1990).
Jakarta:
Binarupa Aksara.
Gaya Chicago
Pitman business english 1.
.
Jakarta:
Binarupa Aksara,
1990.
Text.
Gaya MLA
Pitman business english 1.
.
Jakarta:
Binarupa Aksara,
1990.
Text.
Gaya Turabian
Pitman business english 1.
Jakarta:
Binarupa Aksara,
1990.
Print.