Cita APA (7a ed.)
(2011). <The> world almanac and book of facts 2011: <the> authority since 1868. World Almanac Books.
Cita Chicago Style (17a ed.)
<The> World Almanac and Book of Facts 2011: <the> Authority Since 1868. New York: World Almanac Books, 2011.
Cita MLA (9a ed.)
<The> World Almanac and Book of Facts 2011: <the> Authority Since 1868. World Almanac Books, 2011.
Precaución: Estas citas no son 100% exactas.