Testing warm Comptonization models for the origin of the soft X-ray excess in AGNs P.-O. Petrucci, F. Ursini, A. De Rosa, S. Bianchi, M. Cappi, G. Matt, M. Dadina and J. Malzac A&A, 611 (2018) A59 Published online: 27 March 2018 DOI: 10.1051/0004-6361/201731580