Gaya APA
Sager, Robert J [et.al]. (1989).
World Geography Today .
Texas:
Holt, Rinehart and Winston.
Gaya Chicago
Sager, Robert J [et.al].
World Geography Today.
Texas:
Holt, Rinehart and Winston,
1989.
Buku.
Gaya MLA
Sager, Robert J [et.al].
World Geography Today.
Texas:
Holt, Rinehart and Winston,
1989.
Buku.
Gaya Turabian
Sager, Robert J [et.al].
World Geography Today.
Texas:
Holt, Rinehart and Winston,
1989.
Buku.