Gaya APA
National Geographic Vol. 157, No.1 January 1978. (1978).
Washington, D.C.:
National Geographic Society.
Gaya Chicago
National Geographic Vol. 157, No.1 January 1978.
.
Washington, D.C.:
National Geographic Society,
1978.
Text.
Gaya MLA
National Geographic Vol. 157, No.1 January 1978.
.
Washington, D.C.:
National Geographic Society,
1978.
Text.
Gaya Turabian
National Geographic Vol. 157, No.1 January 1978.
Washington, D.C.:
National Geographic Society,
1978.
Print.