Analytical study of magnetization dynamics driven by spin-polarized currents R. Bonin, C. Serpico, G. Bertotti, I. D. Mayergoyz and M. d'Aquino Eur. Phys. J. B, 59 4 (2007) 435-445 Published online: 16 February 2007 DOI: 10.1140/epjb/e2007-00051-5