@article{DE_1967_3_1_a4,
     author = {A. M. Nakhushev},
     title = {On a boundary value problem for an equation of mixed type with two lines of parabolic degeneration},
     journal = {Differencialʹnye uravneni\^a},
     pages = {45--58},
     publisher = {mathdoc},
     volume = {3},
     number = {1},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1967_3_1_a4/}
}