?url_ver=Z39.88-2004&rft_id=10.4018%2F978-1-4666-3679-8.ch019&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.aulast=Ahmad&rft.au=Ahmad%2C+M.&rft.aufirst=M.&rft.isbn=9781466636798&rft.date=2013&rft.btitle=A+software+engineering+approach+for+access+control+to+multi-level-security+documents&rft.genre=book