@article{DE_2003_39_6_a7,
     author = {K. B. Sabitov and G. G. Sharafutdinova},
     title = {The {Tricomi} {Problem} for a {Mixed} {Type} {Equation} with {Two} {Orthogonal} {Degeneration} {Lines}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {788--800},
     publisher = {mathdoc},
     volume = {39},
     number = {6},
     year = {2003},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2003_39_6_a7/}
}