?url_ver=Z39.88-2004&rft_id=10.1109%2FNatPC.2011.6136439&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.aulast=Armi&rft.au=Armi%2C+N.&rft.aufirst=N.&rft.isbn=9781457718847&rft.title=Sensing+and+access+over+imperfect+channel+in+opportunistic+spectrum+access+system&rft.date=2011&rft.genre=proceeding