@article{DAN_1962_146_3_a6,
     author = {S. G. Krein and G. I. Laptev},
     title = {Boundary-value problems for an equation in {Hilbert} space},
     journal = {Doklady Akademii Nauk},
     pages = {535--538},
     year = {1962},
     volume = {146},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1962_146_3_a6/}
}