@article{RM_1979_34_5_a11,
     author = {A. A. Shkalikov},
     title = {On~the~basis problem of~the~eigenfunctions of~an~ordinary differential operator},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {249--250},
     publisher = {mathdoc},
     volume = {34},
     number = {5},
     year = {1979},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1979_34_5_a11/}
}