APA Style
National Geographic. (2011).
USA:
National Geographic Society.
Chicago Style
National Geographic.
Vol.220/No.4/October 2011.
USA:
National Geographic Society,
2011.
Books.
MLA Style
National Geographic.
Vol.220/No.4/October 2011.
USA:
National Geographic Society,
2011.
Books.
Turabian Style
National Geographic.
USA:
National Geographic Society,
2011.
Books.