@article{DAN_1960_131_4_a6,
     author = {N. M. Leontovich},
     title = {The asymptotic expansion of boundary value problems for partial differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {742--745},
     publisher = {mathdoc},
     volume = {131},
     number = {4},
     year = {1960},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1960_131_4_a6/}
}