Gaya APA
Writing Skills 1. (2014).
Singapura:
Alston Publishing House.
Gaya Chicago
Writing Skills 1.
.
Singapura:
Alston Publishing House,
2014.
Text.
Gaya MLA
Writing Skills 1.
.
Singapura:
Alston Publishing House,
2014.
Text.
Gaya Turabian
Writing Skills 1.
Singapura:
Alston Publishing House,
2014.
Print.