The Global Top Selling Digital Singles of 2011, IFPI Digital Music Report 2012(PDF), International Federation of the Phonographic Industry: 7, 2012-01-23, (原始内容存档(PDF)于2016-12-05) (美国英语)
The Global Top Selling Digital Singles of 2011, IFPI Digital Music Report 2012(PDF), International Federation of the Phonographic Industry: 7, 2012-01-23, (原始内容存档(PDF)于2016-12-05) (美国英语)