TY - JOUR AU - V. A. Kondratiev AU - S. D. Ăˆidel'man AU - T. G. Pletneva TI - On positive solutions of partial differential equations in a neighborhood of a smooth noncharacteristic hypersurface JO - Doklady Akademii Nauk PY - 1972 SP - 279 EP - 282 VL - 204 IS - 2 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/DAN_1972_204_2_a4/ LA - ru ID - DAN_1972_204_2_a4 ER -