Wallis, R.(1999). Contested Collective Administration of Intellectual Property Rights in Music : The Challenge to the Principles of Reciprocity and Solidarity: The Challenge to the Principles of Reciprocity and Solidarity. European Journal of Communication, 14(1), 5-35. doi:10.1177/0267323199014001001

Wallis, Roger. "Contested Collective Administration of Intellectual Property Rights in Music : The Challenge to the Principles of Reciprocity and Solidarity: The Challenge to the Principles of Reciprocity and Solidarity". European Journal of Communication, 14.1 ( 1999 ): 5-35.