@article{DAN_1976_227_2_a6,
     author = {L. A. Kotko and S. G. Krein},
     title = {On the completeness of the system of eigen and associated functions of boundary value problems with a parameter in the boundary conditions},
     journal = {Doklady Akademii Nauk},
     pages = {288--290},
     publisher = {mathdoc},
     volume = {227},
     number = {2},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1976_227_2_a6/}
}