Retrieved on August 29, 2010 ^   Kirkpatrick, David (2010).  The Facebook Effect: The Inside Story of the Company That Is Connecting the World .  New York, New York : Simon & Schuster . pp. 20–21.  ISBN   978-1-4391-0211-4 . Retrieved November 9, 2010 . ^   Spiegel, Rob (December 20, 2010).  "Zuckerberg Goes Searching