@article{DAN_1981_260_5_a12,
     author = {S. M. Ponomarev},
     title = {On some boundary value problems for equations of mixed type with a spectral parameter},
     journal = {Doklady Akademii Nauk},
     pages = {1074--1078},
     publisher = {mathdoc},
     volume = {260},
     number = {5},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1981_260_5_a12/}
}