Associated Absorption at Low and High Redshift
  Combining information on absorbing material in AGN from X-ray and the UV creates a powerful investigative tool. Here we give examples from both low and high redshift. 
Martin Elvis (1), Smita Mathur (1), Belinda J. Wilkes (1), Fabrizio   Fiore (1,2), Paolo Giommi (2) and Paolo Padovani (2). ...