X-ray emission from classical T Tauri stars: accretion shocks and coronae? H. M. Günther, J. H. M. M. Schmitt, J. Robrade and C. Liefke A&A, 466 3 (2007) 1111-1121 Published online: 24 April 2007 DOI: 10.1051/0004-6361:20065669