Constraining the fraction of Compton-thick AGN in the Universe by modelling the diffuse X-ray background spectrumA. Akylas, A. Georgakakis, I. Georgantopoulos, M. Brightman and K. NandraA&A, 546 (2012) A98DOI: https://doi.org/10.1051/0004-6361/201219387
