%0 Journal Article %A I. O. Rasskazov %T The Riemann problem for the weakly perturbed $2\times2$ hyperbolic systems %J Zapiski Nauchnykh Seminarov POMI %D 2002 %P 194-206 %V 285 %I mathdoc %U http://geodesic.mathdoc.fr/item/ZNSL_2002_285_a13/ %G ru %F ZNSL_2002_285_a13