@article{DE_1991_27_4_a25,
     author = {V. A. Kostin},
     title = {The {Cauchy} problem for hyperbolic {Tricomi} equations with initial data not on the line of parabolic degeneration},
     journal = {Differencialʹnye uravneni\^a},
     pages = {716--717},
     publisher = {mathdoc},
     volume = {27},
     number = {4},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1991_27_4_a25/}
}