Simultaneous X-ray and optical observations of S5 0716+714 after the outburst of March 2004 L. Foschini, G. Tagliaferri, E. Pian, G. Ghisellini, A. Treves, L. Maraschi, F. Tavecchio, G. Di Cocco and S. R. Rosen A&A, 455 3 (2006) 871-877 Published online: 16 August 2006 DOI: 10.1051/0004-6361:20064959