APA Style
National geographic : population no. 4. (1998).
Washington, D.C.:
the National Geographic Society.
Chicago Style
National geographic : population no. 4.
october 1998.
Washington, D.C.:
the National Geographic Society,
1998.
Text.
MLA Style
National geographic : population no. 4.
october 1998.
Washington, D.C.:
the National Geographic Society,
1998.
Text.
Turabian Style
National geographic : population no. 4.
Washington, D.C.:
the National Geographic Society,
1998.
Print.