@article{TM_2009_266_a12,
     author = {S. P. Tsarev and E. S. Shemyakova},
     title = {Differential {Transformations} of {Parabolic} {Second-Order} {Operators} in the {Plane}},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {227--236},
     publisher = {mathdoc},
     volume = {266},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_2009_266_a12/}
}