"ČNS IFPI" (in Czech). Hitparáda – Digital Top 100 Oficiální. IFPI Czech Republic. Note: Select 12. týden 2021 in the date selector. Retrieved March 31, 2021.
hitparada.ifpicr.cz
"ČNS IFPI" (in Slovak). Hitparáda – Singles Digital Top 100 Oficiálna. IFPI Czech Republic. Note: Select SINGLES DIGITAL - TOP 100 and insert 202112 into search. Retrieved March 31, 2021.