APA Style
National Geographic. (2013).
USA:
National Geographic Society.
Chicago Style
National Geographic.
Vol.223/No.4/April 2013.
USA:
National Geographic Society,
2013.
Books.
MLA Style
National Geographic.
Vol.223/No.4/April 2013.
USA:
National Geographic Society,
2013.
Books.
Turabian Style
National Geographic.
USA:
National Geographic Society,
2013.
Books.