Simultaneous X-ray spectroscopy of YY Gem with Chandra and XMM-Newton B. Stelzer, V. Burwitz, M. Audard, M. Güdel, J.-U. Ness, N. Grosso, R. Neuhäuser, J. H. M. M. Schmitt, P. Predehl and B. Aschenbach A&A, 392 2 (2002) 585-598 Published online: 30 August 2002 DOI: 10.1051/0004-6361:20021188