@article{SM_1981_39_3_a6,
     author = {N. A. Shananin},
     title = {On local unsolvability of differential equations with weighted derivatives},
     journal = {Sbornik. Mathematics},
     pages = {417--428},
     publisher = {mathdoc},
     volume = {39},
     number = {3},
     year = {1981},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1981_39_3_a6/}
}