@article{DE_1978_14_7_a20,
     author = {I. V. Maiorov},
     title = {A problem for equations of mixed type with a closed line of degeneracy},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1321--1323},
     publisher = {mathdoc},
     volume = {14},
     number = {7},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1978_14_7_a20/}
}