@article{MZM_1980_28_4_a5,
     author = {M. I. Matiichuk and I. D. Pukal'skii},
     title = {A problem with directional derivative for degenerate parabolic equation},
     journal = {Matemati\v{c}eskie zametki},
     pages = {533--544},
     publisher = {mathdoc},
     volume = {28},
     number = {4},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1980_28_4_a5/}
}