%0 Journal Article %A Yu. G. Rykov %T Propagation of singularities of shock wave type in a~system of equations of two-dimensional pressureless gas dynamics %J Matematičeskie zametki %D 1999 %P 760-769 %V 66 %N 5 %I mathdoc %U http://geodesic.mathdoc.fr/item/MZM_1999_66_5_a11/ %G ru %F MZM_1999_66_5_a11