@article{DE_1979_15_8_a13,
     author = {A. G. Kuz'min},
     title = {Investigation of boundary value problems for an equation of mixed type with a family of characteristics that cross the line of degeneracy twice},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1478--1490},
     publisher = {mathdoc},
     volume = {15},
     number = {8},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1979_15_8_a13/}
}