@article{VNGU_2016_16_3_a1,
     author = {G. V. Demidenko},
     title = {Quasielliptic operators and equations not solvable with respect to the highest order derivative},
     journal = {Sibirskij \v{z}urnal \v{c}istoj i prikladnoj matematiki},
     pages = {15--26},
     publisher = {mathdoc},
     volume = {16},
     number = {3},
     year = {2016},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VNGU_2016_16_3_a1/}
}