Reporter, Jennifer (October 31, 2008). "Britney's Next Single: 'Circus'". BritneySpears.com. Brandcasting Unlimited. Archived from the original on December 17, 2008. Retrieved November 9, 2010.
Reporter, Jennifer (October 31, 2008). "Britney's Next Single: 'Circus'". BritneySpears.com. Brandcasting Unlimited. Archived from the original on December 17, 2008. Retrieved November 9, 2010.