Gaya APA
Serba gratis di internet. (2009).
:
Daras Books.
Gaya Chicago
Serba gratis di internet.
.
:
Daras Books,
2009.
Text.
Gaya MLA
Serba gratis di internet.
.
:
Daras Books,
2009.
Text.
Gaya Turabian
Serba gratis di internet.
:
Daras Books,
2009.
Print.