Gaya APA
Mastering American english. ().
New York:
McGrawhill.
Gaya Chicago
Mastering American english.
.
New York:
McGrawhill,
.
Text.
Gaya MLA
Mastering American english.
.
New York:
McGrawhill,
.
Text.
Gaya Turabian
Mastering American english.
New York:
McGrawhill,
.
Print.