TY - JOUR AU - P. I. Kaleda TI - Singular systems on the plane and in space JO - Trudy Seminara im. I.G. Petrovskogo PY - 2011 SP - 204 EP - 228 VL - 28 IS - 28 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TSP_2011_28_28_a7/ LA - ru ID - TSP_2011_28_28_a7 ER -