Cita APA (7th ed.)
World Almanac Books. (2006). The world almanac and book of facts 2006. World Almanac Books.
Cita Chicago (17th ed.)
World Almanac Books. The World Almanac and Book of Facts 2006. New York: World Almanac Books, 2006.
Cita MLA (9th ed.)
World Almanac Books. The World Almanac and Book of Facts 2006. World Almanac Books, 2006.
Atenció: Aquestes cites poden no estar 100% correctes.