APA
(2007). The World almanac and book of facts 2007. New York: The World Almanac Education Group.
Chicago
2007. The World almanac and book of facts 2007. New York: The World Almanac Education Group.
Harvard
(2007). The World almanac and book of facts 2007. New York: The World Almanac Education Group.
MLA
The World almanac and book of facts 2007. New York: The World Almanac Education Group. 2007.