@article{DAN_1976_230_1_a5,
     author = {V. A. Il'in},
     title = {On the properties of a reduced system of eigenfunctions and associated functions of a {Keldys} bundle of ordinary differential operators},
     journal = {Doklady Akademii Nauk},
     pages = {30--33},
     publisher = {mathdoc},
     volume = {230},
     number = {1},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1976_230_1_a5/}
}