Submillimeter and X-ray observations of an X class flare C. G. Giménez de Castro, G. Trottet, A. Silva-Valio, S. Krucker, J. E. R. Costa, P. Kaufmann, E. Correia and H. Levato A&A, 507 1 (2009) 433-439 Published online: 27 August 2009 DOI: 10.1051/0004-6361/200912028