@TechReport{coregrid:tr0154,
      AUTHOR = {Stagni, Federico and Arenas, Alvaro E. and Aziz, Benjamin},
      TITLE = {On Usage Control in Data Grids},
      YEAR = {2008},
      MONTH = {June},
      NUMBER = {TR-0154},
      INSTITUTION = {Institute on Knowledge and Data Management, CoreGRID - Network of Excellence},
      URL = {http://www.coregrid.net/mambo/images/stories/TechnicalReports/tr-0154.pdf},
      KEYWORDS = {WP2}
}