Cita APA (7a ed.)
(2007). The world almanac and book of facts 2007. World Almanac Education Group.
Cita Chicago Style (17a ed.)
The World Almanac and Book of Facts 2007. New York: World Almanac Education Group, 2007.
Cita MLA (9a ed.)
The World Almanac and Book of Facts 2007. World Almanac Education Group, 2007.
Precaución: Estas citas no son 100% exactas.