@article{DE_1970_6_4_a13,
     author = {N. I. Brisch},
     title = {On mixed problems for certain semihyperbolic equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {705--720},
     publisher = {mathdoc},
     volume = {6},
     number = {4},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_4_a13/}
}