@article{DAN_1964_157_5_a6,
     author = {Z. O. Mel'nik},
     title = {On a general mixed problem},
     journal = {Doklady Akademii Nauk},
     pages = {1039--1042},
     year = {1964},
     volume = {157},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1964_157_5_a6/}
}