Time Inc. Home Entertainment & Encyclopaedia Britannica. (2009). Time almanac 2009. Encyclopaedia Britannica.
Cita Chicago (17th ed.)Time Inc. Home Entertainment i Encyclopaedia Britannica. Time Almanac 2009. Chicago: Encyclopaedia Britannica, 2009.
Cita MLA (9th ed.)Time Inc. Home Entertainment i Encyclopaedia Britannica. Time Almanac 2009. Encyclopaedia Britannica, 2009.
Atenció: Aquestes cites poden no estar 100% correctes.