Hard X-ray variability of active galactic nuclei V. Beckmann, S. D. Barthelmy, T. J.-L. Courvoisier, N. Gehrels, S. Soldi, J. Tueller and G. Wendt A&A, 475 3 (2007) 827-835 Published online: 17 September 2007 DOI: 10.1051/0004-6361:20078355