Nielsen Business Media, Inc. (May 9, 2009). Billboard. Nielsen Business Media, Inc. p. 59. Archived from the original on April 27, 2018. {{cite book}}: |author= has generic name (help)
Nielsen Business Media, Inc. (May 9, 2009). Billboard. Nielsen Business Media, Inc. p. 59. Archived from the original on April 27, 2018. {{cite book}}: |author= has generic name (help)