@article{DE_1986_22_1_a12,
     author = {M. S. Salakhitdinov and Z. Kadyrov},
     title = {A problem with a normal derivative for an equation of mixed type with nonsmooth lines of degeneracy},
     journal = {Differencialʹnye uravneni\^a},
     pages = {103--114},
     publisher = {mathdoc},
     volume = {22},
     number = {1},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1986_22_1_a12/}
}