"ČNS IFPI" (chexcha). Hitparáda – Digital Top 100 Oficiální. IFPI Czech Republic. Note: Change the chart to CZ – SINGLES DIGITAL – TOP 100 and insert 202121 into search. Qaraldi: 31-may 2021-yil.
„ČNS IFPI“ (cs). IFPI ČR. 3-noyabr 2020-yilda asl nusxadan arxivlangan. Qaraldi: 31-may 2021-yil.