Gaya APA
National Geographic Indonesia. (2003).
:
.
Gaya Chicago
National Geographic Indonesia.
Cet.1.
:
,
2003.
REFERENSI.
Gaya MLA
National Geographic Indonesia.
Cet.1.
:
,
2003.
REFERENSI.
Gaya Turabian
National Geographic Indonesia.
:
,
2003.
REFERENSI.