"ČNS IFPI" (in Czech). Hitparáda – Radio Top 100 Oficiální. IFPI Czech Republic. Note: Select 26. týden 2009 in the date selector. Retrieved November 25, 2014.
hitparadask.ifpicr.cz
"ČNS IFPI" (in Slovak). Hitparáda – Radio Top 100 Oficiálna. IFPI Czech Republic. Note: insert 200920 into search. Retrieved November 25, 2014.