@inproceedings{AUS04B, author = {Andreas U. Schmidt and Omid Tafreschi and Ruben Wolf}, title = {{I}nteroperability {C}hallenges for {DRM} {S}ystems}, year = {2004}, booktitle = {Reviewed Paper. IFIP/GI Workshop on Virtual Goods, Ilmenau (Germany), 28-29 May 2004, online publication pp. 125--136. Available from \href{http://virtualgoods.tu-ilmenau.de/2004/program.html}{http://virtualgoods.tu-ilmenau.de/2004/program.html}}, note = {Published exclusively on the Web} }