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.
MTV News Staff (September 21, 2009). "EMA Nominations Announced". MTV. MTV Networks. Archived from the original on October 30, 2009. Retrieved January 5, 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.
MTV News Staff (September 21, 2009). "EMA Nominations Announced". MTV. MTV Networks. Archived from the original on October 30, 2009. Retrieved January 5, 2010.