@article{DAN_1961_136_2_a3,
     author = {V. I. Zhegalov},
     title = {Boundary value problem for a mixed-type equation of higher order},
     journal = {Doklady Akademii Nauk},
     pages = {274--276},
     publisher = {mathdoc},
     volume = {136},
     number = {2},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_136_2_a3/}
}