?url_ver=Z39.88-2004&rft_id=PQ+ETD%3A593875&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adissertation&rft.au=Ashton%2C+C.E.&rft.aufirst=C.E.&rft.aulast=Ashton&rft.tpages=94&rft.title=A+study+of+warm+absorbers+in+active+galactic+nuclei.&rft.date=2005&rft.degree=Masters&rft.inst=University+of+London