1. Digital Music Report 2013: Engine of a Digital World;IFPI,2013
2. Digital Music Report 2012: Expanding Choice, Going Global;IFPI,2012
3. Understanding the Music Industries;Anderton,2013
4. Digital Revenues Overtake Physical in UK Recorded Music Market, 31 May 2012;BPI,2012
5. Measuring the Effect of Music Downloads on Music Purchases;Zentner;J. Law Econ.,2004