Gaya APA
IPS Geografi 3. (1989).
Upper Saddle River, NJ:
Penebar Plus.
Gaya Chicago
IPS Geografi 3.
.
Upper Saddle River, NJ:
Penebar Plus,
1989.
Text.
Gaya MLA
IPS Geografi 3.
.
Upper Saddle River, NJ:
Penebar Plus,
1989.
Text.
Gaya Turabian
IPS Geografi 3.
Upper Saddle River, NJ:
Penebar Plus,
1989.
Print.