A long-term study of AGN X-ray variability - Structure function analysis on a ROSAT-XMM quasar sampleR. Middei, F. Vagnetti, S. Bianchi, F. La Franca, M. Paolillo and F. UrsiniA&A, 599 (2017) A82DOI: https://doi.org/10.1051/0004-6361/201629940
