Gaya APA
Sager, Robert J [et.al]. (1992).
World Geography Today (Revisi).
USA:
Holt, Rinehart and Winston.
Gaya Chicago
Sager, Robert J [et.al].
World Geography Today.
Revisi
USA:
Holt, Rinehart and Winston,
1992.
Buku.
Gaya MLA
Sager, Robert J [et.al].
World Geography Today.
Revisi
USA:
Holt, Rinehart and Winston,
1992.
Buku.
Gaya Turabian
Sager, Robert J [et.al].
World Geography Today.
Revisi
USA:
Holt, Rinehart and Winston,
1992.
Buku.