Maximum entropy principle and coherent harmonic generation using a single-pass free-electron laser F. Curbis, A. Antoniazzi, G. De Ninno and D. Fanelli Eur. Phys. J. B, 59 4 (2007) 527-533 Published online: 15 November 2007 DOI: 10.1140/epjb/e2007-00306-1