TY - JOUR AU - G. G. Kazaryan TI - A~characterization of hypoellipticity by estimates from below JO - Trudy Matematicheskogo Instituta imeni V.A. Steklova PY - 1976 SP - 162 EP - 168 VL - 140 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/TM_1976_140_a7/ LA - ru ID - TM_1976_140_a7 ER -