@article{DE_1977_13_1_a23,
     author = {I. N. Lanin},
     title = {A certain boundary value problem for a second order mixed type equation with several parallel lines of degeneracy},
     journal = {Differencialʹnye uravneni\^a},
     pages = {168--169},
     publisher = {mathdoc},
     volume = {13},
     number = {1},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1977_13_1_a23/}
}