Q2237+0305 in X-rays: spectra and variability with XMM-Newton E. V. Fedorova, V. I. Zhdanov, C. Vignali and G. G. C. Palumbo A&A, 490 3 (2008) 989-994 Published online: 17 September 2008 DOI: 10.1051/0004-6361:20078730