XMM-Newton and Chandra measurements of the AGN intrinsic absorption: dependence on luminosity and redshiftA. Akylas, I. Georgantopoulos, A. Georgakakis, S. Kitsionas and E. HatziminaoglouA&A, 459 3 (2006) 693-701DOI: https://doi.org/10.1051/0004-6361:20054632
