TY - JOUR A1 - Hartung, Frank T1 - Mobile DRM Introduction: The Need for Mobile DRM JF - Digital Rights Management : Technological, Economic, Legal and Political Aspects / Becker, Eberhard [u.a.] Y1 - 2003 N1 - Lecture Notes in Computer Science ; 2770 SP - 138 EP - 149 PB - Springer CY - Berlin ER -