Cita APA (7th ed.)

(2012). The World almanac and book of facts, 2012. World Almanac Books.

Cita Chicago (17th ed.)

The World Almanac and Book of Facts, 2012. New York: World Almanac Books, 2012.

Cita MLA (9th ed.)

The World Almanac and Book of Facts, 2012. World Almanac Books, 2012.

Atenció: Aquestes cites poden no estar 100% correctes.