%0 Journal Article %A N. Ya. Kirpichnikova %T Equations for a wave front, rays, and a phase function near a regular region of the caustic formed by space-time rays %J Zapiski Nauchnykh Seminarov POMI %D 1992 %P 92-100 %V 203 %U http://geodesic.mathdoc.fr/item/ZNSL_1992_203_a7/ %G ru %F ZNSL_1992_203_a7