Gaya APA
Geografi. (1987).
Upper Saddle River, NJ:
Penebar Plus.
Gaya Chicago
Geografi.
.
Upper Saddle River, NJ:
Penebar Plus,
1987.
Text.
Gaya MLA
Geografi.
.
Upper Saddle River, NJ:
Penebar Plus,
1987.
Text.
Gaya Turabian
Geografi.
Upper Saddle River, NJ:
Penebar Plus,
1987.
Print.