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@article{TM_1976_140_a7, author = {G. G. Kazaryan}, title = {A~characterization of hypoellipticity by estimates from below}, journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova}, pages = {162--168}, publisher = {mathdoc}, volume = {140}, year = {1976}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/TM_1976_140_a7/} }
G. G. Kazaryan. A~characterization of hypoellipticity by estimates from below. Trudy Matematicheskogo Instituta imeni V.A. Steklova, Investigations in the theory of differentiable functions of many variables and its applications. Part 6, Tome 140 (1976), pp. 162-168. http://geodesic.mathdoc.fr/item/TM_1976_140_a7/