@article{RM_1974_29_3_a28,
     author = {O. A. Oleinik and E. V. Radkevich},
     title = {Conditions for the analyticity of all solutions of a~second order linear equation},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     publisher = {mathdoc},
     volume = {29},
     number = {3},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1974_29_3_a28/}
}