@article{TM_1972_117_a14,
     author = {S. V. Uspenskii},
     title = {The representation of functions defined by a certain class of hypoelliptic operators},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {292--299},
     publisher = {mathdoc},
     volume = {117},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1972_117_a14/}
}